I think the key phrase is that if you push yourself, you can do it. The problem is that after a certain point, i don't want to push myself. Now, I'm not saying that I haven't done things on the bike that I thought I'd never do and I know what seems normal to me astounds my non-cycling friends. But, sometimes I am just as happy doing my 16 mile loop. In fact, most of the time, I am. I've done a century, done 50 mile rides with 5,000 feet of climbing, and I can climb 18% grades (slowly). But the thought of doing those things most of the time, when I sit here and think about it, doesn't thrill me. I keep wondering if I am just a wimp, when I see those people on beater bikes finishing long rides. I mean, I am always happy when I finish doing one of those challenging rides, but in my head, I am never very happy in the beginning of a ride that is challenging. It definitely is in my head, because I always finish, but I guess I will never be one of those people training for a double!