Well I think you have a "natuarl" peak, or peope would have been benching a thousand pounds some time ago!! But as for me
started when I was around 15, but nothing serious till about a year ago, messed around alot, but didnt know anything, so was more of just moving weights around blind!
but I dont think your peak has everything to do with your age, untill you get up there (50's or so)buut the easiese time IMO is from 23-35!