More or Less a Child?

A great deal of the time I feel like I am very childish. I feel like I have no idea how to live in the real world. I think the majority of my goals are completely unrealistic, and I simply don't know how to function as an adult. Then there are other times when I think it's the rest of society that is childish. When you really think about it, what is childhood all about? Sure, it's about fantasy and imagination and and a general disregard for societal functions (all of which I have managed to maintain in abundance) but it's also about a focus on yourself; your own interests, your own needs, and many times your own little imagined world. How different is that really from the way most people live their lives? Is there really any difference between a child who believes there is nothing in the world more important than his toys and an adult who does nothing with his life but earn money to buy expensive cars and designer clothes? Is it more childish to have unrealistic goals for the impact your life will have, or to just decide to live only for yourself and your own tiny chunk of the world? Is it really an indication of immaturity that I am unable to accept the inevitability of mediocrity? I guess probably it is, if only by our society's standards.