Fast is a relative term. I'm faster than some and slower than some. The faster I got the higher the bar got raised. The guys that I look at and think 'that guys fast' are looking at other guys thinking the same thing. Even at the pro level on any given day the pro's are looking at another rider and thinking he's fast.

FWIW 20mph would be a moderate pace for our fast group ride (taking out the stoplights).