Doing whatever it takes to make you happy and for some people, at least they're being who they are and not the stereotype of who they're supposed to be. Your inner child. Most people believe that age defines who you are and if you don't "act your age", you're immature. "Mature" people seem to be very depressed and settle for everything even if they don't want it.
Stuck up bitch: Why is that girl coloring in a spongebob coloring book? She's so immature.
Other person: At least she's doing what makes her happy, bitch.
Amazingly awesome. Not commonly used but most people who do use this term are serious druggies or potheads. The first time the term was used was by a girl who was stoned out of her mind and used it to describe a rainbow colored slinky.
druggie: *smokes a joint* Spongebob is oober pimpin'!!!