I can't answer any more questions. There are a bunch of kids on this thread.
If you are under 75, just be thankful and enjoy the rides. If I can go another 3 years, I'll be happy.
Since my wreck (which almost did me in ---- 1.5 days in ER, with bleeding on the frontal lobe), I am lucky if I can get in 25 miles per week. (I go on the greenway that goes just past the hospital - they can take me right in, I won't have to go far to the ER). I still enjoy it though, so who knows. My next purchase will be to attach a battery to my bike and help me to go up the hills.