Out of curiosity, how do you determine what "hard" is? What is your basic yardstick for determining performance?

I don't train for anything either, and I never have a plan in place. Hell, half the time I go out I don't have a plan of where I'm going. I just ride around. But I know that when I do a century on Monday, my body is gonna take it easy on Tuesday, whether by brain wants to or not.

If you haven't had days where you simply can't ride faster, you're not riding as hard as you think. Or, more likely, if you're only riding 3-5 days a week, you are recovering. You're recovering by not riding.