At least part of it is the Law of Undulation that C.S. Lewis refers to in the Screwtape Letters. It's just built into our humanity, a hard-wired (for those that feel more comfortable with that concept than referring to our creator and all that) mechanism probably in place to keep us from burning out, hurting ourselves, and becoming hopelessly OCD.

What happens if you take the time off from riding? You fail to qualify for the TdF next year?

Perhaps some of it is how competitive the ride reports have come. I thought I got a bike to ride around and have fun, not to crush some souls.

Of course, crushing souls has some benefits. But it's a mistake to think I'm a failure as a cyclist because I only turned in 50 miles this past week. And that's a lot for the average citizen. Just not the average BFer.