ha you guys are crazy, if your in your 20's your not old, look at skateboarding, half the pro's are over 30 and killing it, look at tod richards, he's like 40 and he still kills it.
there are some people who's body's just cant take hits as hard as others. but if your one of those people, who care's? you dont need to be all technical, do comps and ski like its the superbowl, just chill and fuck around. im probably somebody who is blessed with a good body that can take hard hits, but i still dont give a shit about being better than others, impressing people, or progressing like crazy, if im not smiling then i quit what im doing. ill try new stuff all the time but i spend most my time just cruising around and fucking around on stuff. its really nice when you have no desire or anything to turn pro or get a ton of sponsors or whatever, cause you really can just ski how ever the hell you want.
im 20, and i can take more abuse than 5 years ago, probably cause im in better shape, stronger, and more ballsy. so i havent really felt any effects of growing older yet.
there are some people i know who couldnt run half a mile or ski a day without complaining about their knees hurting or their back being sore or whatever when they were 13. and theres people i know who are in their mid 30's that do other sports and have no problem taking huge crashes and getting back up like its nothing.
it just depends on if your in shape, and it depends on the individual, alot more than age i think.