Well, I started backpacking at 52, and the following year I bought the first bicycle I'd ridden since I was 17, which turned into my primary transportation. So yeah, I'm going to go ahead and try mountain biking. I'll probably not ride down gnarly steep hills at 40 mph, and I'll be wearing body armor, as I'd like to avoid broken bones if I can. Nice to know I will have good company in my insanity.