Jump from a non-lethal bridge into a body of water
Because it's amazing and fun. Jumping and falling through the air, almost flying and then landing safely into cool, refreshing water? That sounds pretty nifty to me.

Laugh and Cry at the same time!
Because it's baffling and confusing and hilarious at the same time! I did it once and I actually entertained myself. Eventually I stopped crying 'cause I couldn't stop laughing. Ha ha ha, ok...i admit it's pretty weird.

Play with someone's hair
It's the funest thing in the world to mess with someone's doo and have them react as though you just set their hair on fire when they finally see the results.

Learn to cartwheel
It's recreational AND a skill. Ha ha ha. Plus the first time you try it it sends your world topsy turvy for a sec which is lovely and, for me (for some reason) unexpected. Although i just ruined the surprise for whoever reads this so it's no longer unexpected. Sorry :)

Learn to do something with your hands
it makes you feel accomplished and whenever you use or wear what ever you made you remember that "That's right, I made this AND it still works/ looks great" :) Causing warm and fuzzy feelings inside (or for guys Manly Man Pride on the inside) (rhymes!)