Sadie, I kinda think the same thing too.

What got me to thinking about this was a friend's dad bought his first *real* road bike. Prior to this he used to ride an old mtb around the neighborhood and would ride 12 miles or so on occasion. On his first ride on the new road bike, he did 30+ miles the first time. I've noticed too when I started riding longer distances on the road bike this spring, I was much stronger than I anticipated and could go further distances with less fatigue.