I only started to understand the value of stretching in my 60s. On a tour in my 20s, I was bucking a headwind each day, and found a partner to swap drafting with. I found him at a campground - the worst thing about riding is that you only see people who ride at your speed if they are going the other way. Anyway, I was a commuter, used to leaving for work a bit late and sprinting through traffic. He was a strictly recreational rider, used to a proper warm-up. I'd have to ride my brakes for the first couple of miles while he got up to speed. My body was quite used to the cold start. One morning, I found a flat tire to fix before I could leave, and found myself almost dizzy from having started breathing hard in advance, quite unconsciously.