Well, I am 29. Still, I am being told that I play like child with all that bikes I always say then - the difference between men and boys is in the price of their toys. It never works.
The oldest by far then at 56 - and enjoying my riding more than I have in a long time. Now that I don't race much I don't worry about times and speeds and all that stuff as much as I did, and I just go out and find and work on new routes ( the more technical the better), ride nice bikes (especially singlespeeds) and enjoy the company of a few good riding mates - the great thing is that no-one expects much from guys my age so all that "peer group" pressure is removed, plus it's always good when you can give someone less than half your age something to think about .
This isn't to say that I wouldn't like to be 35 again - of course I would, but I believe I'm a nicer person now than I used to be and (most important this ) a far better technical rider even if I don't have the speed I once had.