My previous post about rationality, irrationality and beyond might appear to be matter of fact; but it is not. The most important part of adulthood is being habituated to the world. People do not discover the limits of the world by reaching at it and trying to go beyond but by stopping to try (This is the root of assumed limits of the self.). Being habituated with the world, is probably the basic reason why adults are not as lively as kids because as kids we were not habituated with the world.
According to Einstein, imagination is more important than knowledge. As a part of being adults, our imagination also starts following some patterns that we build up over time. That is why a few people can claim to think out of the box.
To clarify the point I would like to give two approaches to things. The first one is to know all the rules and work within the boundaries of rules. The second one is to use your imagination to decide what you want to do and while attempting ways to do it, discover the rules. It should be clear that most adults prefer the first approach while kids take the second way of doing things.
Inventors in all fields have very strong imagination for the very same reason. They are usually considered childish too.
Thus there is a rational way of life which usually puts you on the safer side of affairs; there is an irrational (may be interesting and more lively because of being childish at times) way of life and there is a deeper understanding beyond [like Zen].
