If you can taste last night's dinner, it's fast.

If you never see anything but your stem and part of your front wheel, it's fast.

If your back hurts like crazy but you know that to sit up and stretch would catch a faceful of wind taking you off the back, it's fast.

If you're counting the hills between you and home gauging your effort so as not to get dropped, it's fast.

If you get dropped, it was fast.

If it worries you that the guy in front of you is allowing a gap to grow too big, it's fast.

If someone is yelling at you to pedal down the hill, it's Tuesday.