I think the 20-24 set tends to be very preoccupied finding their way in the world, etc. There's little peripheral available for athletics etc. And... you have to admit, the "I hope I can get a 50 in" mindset is very rare in this given age group. It's like Maslow's hierarchy of needs. At 'our' age, unless we're predisposed or have a specific motivation, we have yet to build our bases. Boozing etc serves as stress reduction while we still find novelty in alcohol and other vices, hanging out with the friends builds that support system we all need for emotional reinforcement. We're still finding our way in the world (aren't we all?) just out of the nest and starting to realize that though Mom wanted us to get married, settle down, etc or go to school, settle down, or whatever- we need to do what we need to do. Oh- and the real world is a freaky amalgamation of being just like high school and nothing like it at all.

As we reach our later 20s and the whole of our 30s to early 40s, we have that support system, or the confidence in ourselves, or both, and boozing has lost much of its novelty, to the point where, having sated our requisite base needs, we are freer to seek out more self-fulfilling and altruistic goals. It's at that point that being able to say "I got my 50 in" is more for *us* than someone else. Also, at that age, we are (generally) out of school and making enough money to start enjoying it. I'm not talking tons, I'm talking not living quite paycheck to paycheck. Here's where it comes in that you can maybe afford to set aside for that entry level or slightly better bike...

30s thru 50s seem to be spent more in self-realization, and there you see more of our cycling demographic, though it's been said "30 is the new 20" as people are living longer, going to school, not getting married as young, etc etc...

I dare not presume too much, though. I'm "not there yet" so to speak. Just observations.