I follow something along those lines.
"Do
it my way, or I do it myself."
Heh heh…not something you can really say to your
CEO heh heh. 
My motto is not necessarily mine, nor is it really a
motto but I quote- it’s Marty Feldman’s (rest in peace), but it applies to me.
[i]
"I am
too old to die young, and too young to grow up,"[/i]
This is the one I live by when I play computer/video
games:
“If at first you don’t succeed…quit.”
A
horrible motto to follow, I know. My sister hates it. 
Here is a classic optimistic motto.
“Don’t get mad. Get GLAD!!!”