I nearly lost my religion one day while trying to change a flat tire. I readily confess to being mechanically challenged, but even I can usually change a flat.

This particular day, however, I couldn't get the lugs off the wheel. I grunted. I groaned. I pushed. I pulled. I beat on the lug wrench with a hammer. But the lugs wouldn't give. Finally I gave up, left the tire unchanged, and stalked into the house, defeated.

Later that day, I vented my frustration to a friend on the phone. "Try turning the lugs the other way," he said offhandedly. Now that, I thought, was a stupid suggestion. Lugs and nuts always tighten when turned clockwise and loosen when turned counterclockwise. Every shade-tree mechanic knows that.

Desperate, however, I gave it a try clockwise. Wonder of wonders, it budged! So did the others. In a matter of moments, I had the flat tire off and the spare mounted. I never would have thought to "tighten" the lugnuts in order to loosen them unless my friend had suggested it. I just ...