So, you geezers who ride your age, or, especially you century riders, just ignore this.
I rode home from a late night University class last night. It was about 15 miles in the dark -- mostly paved but unlit trail, but some road -- an hour and 15 minutes. (Plus I am riding an 8 mile round trip to my new p/t job.)
A few years ago, I was doing 12 to 15 mile rides almost every night, and then 20-25 miles on weekends. I had to quit for a while due to some lung problems. I've just been getting back to riding the 12 mile rides -- which are a lot of uphill at 5,000 to 6,000 above sea level, but some flat trail rides.
Anyway, this was a first step for me in moving toward total commuting. I could have driven, but I didn't. I've really been striving for that car-free lifestyle. I even ride the Huffy down the hill to the grocery store now.