I am 49 and always figured myself a smidgeon old for punk... At school there was a lot of prog rock sloshing about and some of it stuck. I liked Yes, the Moody Blues, Gentle Giant, Jethro Tull, Pink Floyd and ELP, but at first I didn't care much for Genesis (esp Gabriel's overwrought vocals - the music seemed fine); in fact I turned down the chance to see them when they were on in York for 60p or so, around the time of Foxtrot.
Later I came to like Genesis for a few years but ELP I never listen to now, except for curiosity once every ten years (never liked Brain Salad Surgery, though). Pink Floyd and some Yes - Close to the Edge for instance - I still listen to. And King Crimson, sometimes thought to be the progenitors of prog-rock, have had a very varied journey and are still going periodically and sometimes produce an infuriating noise but are often very exciting.