Charlie, and everyone else who has replied to Charlie,
There is a saying that old age is a time when one's youthful playfulness and dreams can be reborn. It sure seems to me like a lot of guys here are saying, "Why wait until old age? Let's reclaim those lost dreams and playful personalities NOW!"
I don't think there's anything wrong with reclaiming your youthfulness, at any age. I understand that we have to grow up and be responsible and put away "childish things"; but here's the secret - only be serious and grownup when you HAVE to be. On your own time, be a playful kid again. Guess what: it's not a crime. After all, would you rather have a friend who is serious and grownup all the time, or a friend who can be fun-loving and playful with you when the situation calls for it?
So break out those treasured mementos of childhood the next time you've got some spare time. Play with them and remember what it was like to be a fun-loving kid. Think of it as exercise - the more you work on your fun-loving personality, the more fun-loving you become, both with yourself and with others.
Thank you, Charlie, for starting this topic, and thanks to everyone else for responding to it. You guys are great!