My first 50 miler:
The training:
That summer, I was doing 10-15 mile rides about 5 days a week (on regular undulating terrain - nothing big), with maybe a 20 miler thrown in once every two weeks. I also did a 30 miler early in the summer. All on mild undulating terrain near my home.

The ride:
The 50 was a fun ride, even in the blazing heat that day. I told my wife the route in case I needed to be rescued. I think I ate a PB&J sandwich before leaving. I took a granola bar and two water bottles and drank another bottle full on the way back. This was all in the a.m.

I rode 20 miles, stopped for about 20 minute break (saw a cat I knew and we chatted), rode 20 more miles, stopped for another ~10 minute break, then did the last 10 miles. Felt fine for the rest of the day. Which was funny, because I was spent after a 30 mile ride earlier that year on easier roads.
I was 42 and in average shape. Not a racer or athlete, I just like riding on my own. I don't know how big the hills were, but some required me to look up at them off in the distance. A good 30 miles was all up n down, with the rest undulating terrain.