I bring my clothes to work on the occasions that I drive, usually several days worth of clothes so they're there, and I don't have to think about it. Today, I went to get dressed, and discovered I had no shirt. Luckily, it was cool here (I didn't get too sweaty on the ride), so I wore my jersey all day.

In the past I've forgotten underwear, which was worse (I'll leave my solution to that problem to your imagination).