Hello 50+ers. I'm right there with you. Not as fast or strong as I used to be, but I enjoy cycling as much as I ever did, probably moreso because I don't feel compelled to ride fast if I don't feel like it.
I got into cycling in the early 70s, during the bike boom. Still ride my vintage steel I had as a kid, a '72 Mercian. I don't do as many group rides as I used to, and most of my miles are now commuting by bike.
I look forward to learning from my fellow baby boomers here.