Why does anyone set up or join a club or a team? People get wrapped up in ventures so they can achieve something for themselves, maybe do something good for their community (or someone else's community).
Learn a bit about yourself...
and the others you're with, have some fun and make a few more friends along the way. There's adrenalin to be had when you're plummeting down a raging river in that giant raft (that suddenly begins to feel rather puny)... there's that amazing sense of satisfaction when you finally get to the top of a 2,000 metre peak and can see for miles...
There's the sense of pride when the kids from Beaver scouts (awww) you and the team have taken over to the park for the day will only play football if YOU are playing too... the sense of relief when you're too high up the tree for the other guy to catch you and get your team out of the game... the sense of enjoyment because that meal you said you'd make for the group really does taste great...