I just cracked 50 this year, and only started riding when I was 32. Now, it's a religion of sorts. If you see a solo guy wandering for hours on the dodgy roads of Massachusetts on a red bike with the label Commonwealth (custom built) on a Saturday or Sunday, perhaps wearing team kits from FdJ, Movistar, or Maia Milaneza and - the dead giveaway! - lugging a Camelbak with a large block of ice inside, say hello and toss a lie along the lines of "God, you look good for your age". That type of thing gets you friendships for years, if not half-decades.
I'm also off to my first ever organized trip, in the north of Portugal, in October.