Yeah, the part where motorists seem to think of us a chipmunks to squish with their tires is kinda a bummer. The part about you getting back into it at 66 is just awesome. Beware, it is completely addictive. I got back into it Sept 2012, after a 20 year hiatus, and it has been a Godsend. Saved my sanity, improved my health after a serious bout with some nasty stuff in my bloodstream and bone marrow. So, I went from my 20 year old Cannondale to now owning 6 great bikes. Yes, I may have gone overboard, but I am in heaven with this sport. I'm so crazy I bought a fat bike and ride out in the cold and snow every chance I get. You will be shocked at what this does for you if you pursue it. My first ride was 1.68 miles and I thought I was going to die. By last summer, I was doing near-Century rides, my longest was 87 miles round trip. I think the mental benefit is better than the physical benefit, and that is extremely substantial. To ride is pure freedom, a chance to set aside my problems for hours at a time. I just joined a beginning triathlon team at my gym, and I am completely psyched to get back on the road on my new road bike. Finally, we have a facebook group going for the tri-team, in 4 days I found 3 willing riding partners to train with me, something I have wanted since last year but never could hook up with anyone.
Dude, go for it, it will rock !