Some of us think we regularly climb some killer hills, but others of us put the first group to shame. There's huge variation of terrain. The hillier it is, the more we shrug off the hills. I live in a moderately hilly part of New Jersey. I grew up in Manhattan and remember some of the hills that really killed me. But now when I go back there, they're like molehills, and I laugh at my former self for thinking they were tough hills.

About three years ago, I took a ride in Vermont. I nearly fainted on one hill, because I kept pushing myself. I finally stopped, and I had to stand there for several minutes before I could continue.