I notice lots of things but one that impresses are the 70+ YO's sporting tennis shoes, white sox and hauling on a grindy, noisy JC Penney or standard big box store ride! There's a few in the college town and ride with no mercy, great pace. Come to think of it, they don't even bother wearing helmets.

On the other spectrum, I've thought to have seen it all until Bibendum! Trying to be respectful but use your imagination. This fellow was sporting a full white thin body suit (and was badly gasping for air at the rest point). Vaguely recall the bike but it was something very current.