The Premise
Destined to be just another member of the BnL Starliner, the Axiom, Brandon McCrea grew up just like any other unimportant human on the ship. But unbeknownst to him, his life was about to take a huge turn, for it was set apart to change the history of mankind forever.
A back-story fanfic; not too many details. It basically follows the movie, so I will issue a spoiler alert for those who have not seen it. This shouldn’t get too long - it is almost finished so far, just needs a couple extra sections and it will be completed. 
July - 2754
An emotionless, uniform NAN-E Bot hovered up and down the rows of month-old infants in their box-shaped cribs, making sure each was in their place and sleeping. Right now, everything seemed in place and in order - just as they should. She moved down the rows of cribs to do a quick head check of all the infants and make sure they matched up to the nursery’s database.
The babies were placed in their cribs by name, so the rows were in alphabetical order. All seemed present and sleepy in their cribs. Aaron K., Aaron O., Abraham, Adon C., Adon J. Adon W., Aggie, Alden, Allie, Althea, Ava, Belle, Blake F., Blake P., Brady, Brandon B., Brandon D., Brandon M., Brianna…
NAN-E paused. She moved backwards a few cribs and stopped still again. Where was Brandon M. - the eleven month-old, brown-haired, grey-blue-eyed baby boy?
“Brandon M.,” she stated, “Come on out. It is time for bed. Go to sleep.”
But there was no reply. NAN-E began searching all over the nursery, calling out the baby’s name.
“Brandon M.,” she said again after she couldn’t find him. “This is not a time for games.”
She glanced over, and she happened to notice the door to the nursery wide open. That wasn’t normal at all. She hovered to the door and took a peek outside, at first seeing nothing but humans in their hoverchairs slowly retreating to their cabins.
“Hey, watch it!” a human suddenly cried, manuvering his hoverchair sharply around a small red object on the ground. “Stupid kid. Get back in your hover ring.”
NAN-E was livid. “Brandon M.,” she loudly called. The child who had nearly been hit whirled around at the mention of his name. “Return to the nursery.”
But Brandon refused. He loved messing with the NAN-E Bot. Instead, he rolled onto his back and laughed out loud, grabbing his chubby feet. NAN-E was forced to retrieve him and carry him back to his crib.
Little Brandon M. couldn’t help it - he hated the repetitive scenery and ways of the nursery, and after he had seen only one glimpse of the active world outside those doors, he wanted to know what it was all about. No doubt, he had been out of the nursery more than once, and he would have much rather been hit by that hoverchair than to have to lie silent in his confined crib. As soon as he was set down and the holographic barriers were enabled, he began to cry.
“Brandon M., it is time for bed. Go to sleep,” NAN-E called from the other side of the room, where she stood guard during the night.
Brandon didn’t let up. He only cried harder. Let me out of this place! I want to be free like those other people…!
“Brandon M.,” NAN-E repeated. Brandon wanted to plug his ears. He heard his name enough times in one day to make anyone go insane. “Brandon M… Brandon M…”
Eventually he cried himself to sleep, after crying hard enough to drown out NAN-E Bot’s repetitive words. He dreamed vividly of the world outside of the nursery, wishing that he were able to get out there and explore that bustling reality that was kept so far from his reach.
March - 2769
“Brandon. What are you looking at?”
Brandon snapped out of it, turning to face his best friend, Oliver.
“Huh?” he wondered. Oliver rolled his eyes and lazily kicked at Brandon’s hoverchair.
“You jerk,” he muttered. He sighed loudly and wiggled his toes. “I hate the Lido Deck. I’m too hot here. Let’s go.”
Brandon frowned. “Well, don’t you ever wonder what’s up there?” he asked Oliver, pointing to an elevator on the very north end of the Lido Deck. It lead up to some kind of control room, where Brandon saw a very faint red light. Ever since he had seen it four years ago, he had been wondering what it was. Oliver didn’t look interested.
“Uhh, let me think about that,” he mused, tapping his lip. “Hmm… nope, not really. I’m happier touring the ship while watching trashy shows,” he continued, turning on his hoverchair’s built-in holoscreen. Brandon watched Oliver hover away and merge into the surge of other humans in transit. Biting his lip, he glanced back at the strange room at the front of the ship. If no one else really cared about life outside of hovering around on the Axiom, and if that was all life really was about, why did Brandon get a sense that there was something more…?
Something about that mysterious room spoke to him. There was more out there than what he knew. The question was - would he ever realize what it was? Would he ever be able to break out of the mold that the world was trying to squeeze him into? Or was he stuck in this lot of life for the rest of his existence?
December - 2774
We regret to inform the members of the Axiom that our captain - Captain Kelly O’Brien - passed away early this morning. Please be patient, as we are currently in the process of selecting a new Captain. If you wish to obtain further information, Steward Bots are available to take your questions. Have a great day onboard the Axiom - where YOU are our #1 Priority…!
Brandon quickly ignored the message that appeared on the screen in front of him while he was still asleep and turned off the holoscreen of his hoverchair.
Gah, I hate that, he drowsily thought. You’d think they’d wait to say that after you were awake…
Now that he was awake, there was no point of going back to sleep, and he moved towards the small coffee pot in his cozy cabin. Fresh coffee was always ready for him, no matter what time of day he woke up. He liked that.
As he slowly drank the steaming coffee, he heard the doorbell chime; which was unusual because he never received company - except maybe on his birthday, which his friends usually forgot about anyways.
He set the styrofoam cup down and furrowed his brow, turning his chair around to face the door. “C-come in,” he muttered.
The door slid open, and in zipped a small white robot that seemed to salute him. It was GO-4 - the “police chief” robot of the Axiom. He moved closer to Brandon and gave him a quick scan, then uttered a few quick beeps.
“Uhh… can I help you…?” Brandon mumbled, shrinking back a bit. GO-4 gave some more blips, flashed his red light, and without warning trapped Brandon and his hoverchair in a tractor beam. “Hey… what the hell’s going on?! Where are you taking me?!”
GO-4 didn’t reply and simply led the hoverchair holding the bewildered passenger to a large room where an elevator sat. GO-4 beeped at another large robot stationed over a massive keyboard, and the elevator was activated. Brandon kept his eyes on the large Typing Bot as he was taken into the elevator, wondering what all of this was about.
Wherever I’m going, I hope they have an extra cup of coffee for me, he thought, leaning back with a sigh.
Once they reached the top, the doors were thrust open, and GO-4 brought Brandon into a dark room where a huge, wheel-shaped robot with a gleaming red lens came to life - the ship’s all-important AUTO Pilot. Brandon was released from GO-4’s beam, and AUTO scanned him over as well.
Brandon was getting frustrated with all the fuss. “What do you think I am? Hamburger in a cup?!”
“Name?” AUTO inquired. Brandon cocked his head.
“Br…andon…” he slowly replied.
“Your full name,” AUTO objected. Brandon scoffed.
“I don’t even know my full name,” he laughed. AUTO made a noise that sounded like a groan as he turned to the computer. Using Brandon’s fingerprints, he was able to turn up all the information on the young man, which was stored on file in the ship’s computer.
NAME: Brandon Lee McCrea
D.O.B.: 08-27-2753 (Age 21)
RACE: Caucasian
HAIR: Brown
EYES: Blue/Grey
HEIGHT: N/A
WEIGHT: 347lbs
KNOWN OCCUPATIONS: None
AUTO turned back to Brandon. “Name of former Captain?”
Brandon raised his eyebrow. “…O’Brien…?”
“Correct,” AUTO said. “Name of Starliner?”
“The Axiom.”
“Correct. Current year?”
“2774.”
“Correct. Name of premises?”
Brandon hesitated, looking around the room. He honestly wasn’t sure where he was.
“…Mysterious, dark room with flashy buttons?”
AUTO didn’t seem to understand what Brandon had said for several moments. “Incorrect. This is the Axiom Bridge - the control room of the Supership.”
Brandon sighed. What the heck was all this about? Why did a couple stupid robots have to come and completely ruin his peaceful morning? How dare they deprive him of his coffee, at that!
AUTO continued with his interrogation. “Hold up your left arm.”
Brandon obeyed.
“Verified. Hold up your right arm.”
Again, Brandon held up the other arm.
“Verified.” AUTO pressed another button on the computer, and a strange device came out of the ceiling that looked like some kind of goggles. It stopped short in front of Brandon’s face, and the computer began to speak.
“Place your eyes in the device and look straight ahead,” it commanded. Cautious and nervously, Brandon leaned forward and looked into the device. “Please wait as computer performs retina scan…”
Okay, I’d really like to know what this crap is all about, he thought, waiting for the computer to finish. All of a sudden, robots are swarming around me and asking me dumb questions and scanning my eyes…! I don’t get it!
“Scan completed,” the computer announced. The device disappeared into the ceiling again, and the lights in the room began to dim. A tune behind him caused Brandon to turn his hoverchair around and face a large, holographic video screen, which was now playing a video by the BnL company.
The video went on to explain the duties of the Captain of the Axiom, which were numerous, to say the least. Brandon’s mind was swimming only a minute into the orientation video.
Waaaait, he began to think, losing his concentration on the video, if this is an orientation for the Captain… does that mean… that I’m…?
“Oh, and one more thing you’ll need to remember,” the voice on the video said, breaking Brandon out of his thoughts. “Clap twice, and you’ll get a hot cup in the morning!”
Brandon’s eyes grew wide. That was all he needed to hear - if the Captain got coffee every morning just by clapping twice, he’d take the job!
When the video was through, he turned to AUTO, who was staring at him the entire time.
“So, let me get this straight,” Brandon began, holding up his hands. “You want me to take over the position of Captain of the Axiom?”
“Correct,” AUTO replied. “You must sign computer document before proceeding.”
Brandon was handed a computer pen and asked to sign his name on a small area of the control panel. With a grin, he placed the pen to the pad and wrote out his name the best he could - Brandon Em.
AUTO pressed a button that said “Cancel”. “No,” he objected. “You must sign your name: Captain B. McCrea.”
Brandon frowned. “I don’t know how to write that!” he cried. “And I thought my name was Brandon Em!” AUTO pulled up a screen displaying Brandon’s name.
“Copy the name,” he demanded. Brandon sighed loudly, pressing the pen to the pad all over again. He felt like a kid learning how to write his name in kindergarten.
Jerk, he thought, glancing out of the corner of his eye at AUTO. Once I’m Captain, I’ll show him whose boss!
June - 2805
“Where’s the thingy?” Brandon sputtered, staring at the empty cavity of the EVE Probe in front of him, which was said to have returned from Earth positive.
AUTO was quick to correct him. “Plant.”
“Right, right,” Brandon mumbled, beginning to fumble through the Operation Recolonize manual, which had been given to him after he pressed the green plant button on the control panel. “Well, where is it? Do you think we missed a step?” He read a few paragraphs through, just to make sure, but realized that they hadn’t even gotten past Step One. He turned to AUTO. “Why don’t you scan her, just to be sure.”
AUTO obeyed the command, and he gave EVE a quick scan.
“Contains no specimen,” he announced. “Probe’s memory is faulty.”
Brandon almost felt relieved. “So… we’re not going to Earth?”
“Negative,” AUTO replied. Brandon was feeling better now.
“I guess things go back to normal, huh?”
“Correct, Captain.”
Brandon slapped the book shut. “Well - false alarm; the probe must be defective.” He leaned over. “GO-4, send her to the Repair Ward. Have them run diagnostics on her to make sure she’s not malfunc… ahhh!!!”
There, in the corner, was a small, rusty robot that most certainly did not belong on the perfectly clean Bridge. It was a small Earth-Class bot… a WALL•E, from the looks of it. The little robot happily wheeled over and took Brandon’s large, puffy hand.
“WALL•E!” he cried, introducing himself. When he pulled away, he happened to leave some dirt behind in Brandon’s hand. He looked up at AUTO.
“Have, uhh, ‘WALL•E’ cleaned,” he said, and WALL•E was immediately loaded onto the MV-R with EVE.
Brandon excused AUTO, who returned to his post, and went over to the computer to have the dirt analyzed. The computer brought up a visual description of the substance being scanned.
“Analysis: Foreign contaminant. Substance is a three-phase system composed of various combinations of naturally-derived solids…”
Naw, Brandon thought, turning away. This is boring. Get me another cup of coffee before I…
Wait, did he just hear what he thought he heard?
He zipped back over to the computer. “Earth?” he wondered, staring at the computer screen. Out of curiosity, he glanced back at the small model globe on a stand just a few feet away. “Define Earth.”
Instantly, pictures and videos - more than Brandon could have ever imagined - popped up all over the place; completely filling the screen. More than dirt and water - Earth was a place teeming with life and bustling with variety!
“Earth: The surface of the world as distinct from the sky or sea.”
Brandon McCrea was in complete awe and captivation. A hunger welled inside of him; one he had never felt before - it was a yearn for knowledge.
“Wow,” he breathed, taking in all of the images. “Define sea.”
And so the journey began.
Most of the time, I would take the Captain’s character for granted in the movie. But this truly enjoyable fanfiction takes the reader straight to the heart of his importance and persistance, and lets us also live through the scenes and experience his life. 
But I’ve heard a lot of people say it is worth it in the end.
I’ll change this as soon as I can. Thank you sincerely for pointing it out!