So, I was pondering this a while.
We see in the movie that mind workers can use recall tubes to send certain memories up to Headquarters (Triple Dent Gum 
), and also dispose of memories in the Memory Dump.
However, here’s the pressing question.
Can memories in the Memory Dump be recovered even after they have faded away? I mainly ask based on when Bing Bong faded away, is it possible for him to return by, say, Riley finding an old drawing she may have made of him (assuming she must have taken her stuff from home in Minnesota) and Bing Bong possibly regenerates in her mind.
And… that’s all for my attempt at an Inside Out discussion thread right now. Really wanting to do more sometime soon in the future. 
Until then, I’d like to get a few opinions on this.
That, is an excellent question, JustSoWall-eCrazy. I mean you know how sometimes we can’t remember things when we’re busy with schoolwork and all that, but then after graduating from high school and college or whatever and then haven’t been in school for a while–suddenly there’s flashbacks and other old memories that come back to us, from which we suddenly remember them so easily to the point where any of us start to discuss them with the others. You get me?
evspixarfan2012: I totally get you. 
I mean, you never truly forget memories from your past (unless it’s something from when you were a baby; those are hard for any human being to remember IMO).
But yeah, that would be something to explore in any future Inside Out media (possible sequel, spin-off stories for Pixar storybook collections, short films, etc.). It would be so cool if Riley could remember Bing Bong someday; Joy for sure remembers him.
On a related note along those lines, I imagine (and some people have done it in fanart already on dA and Tumblr) that acting upon that, Joy could place an idea bulb in the console for Riley to be an astronaut and go to the moon to honor Bing Bong’s final wish.