seems like people quit when
- get girlfriend
- drugs
- car
- job
I don't think it's just skating though, seems to me that the majority of people give up on music, hobbies, shows, everything fun you do when you are young, etc... sometime after school and before kids. It's extremely rare I meet someone in a work setting that has anything to talk about other than their kids and the weather. And I seriously think it's because most men let their women dominate them.