What's the worst thing you've done while driving?

Today I'd stopped at a roundabout which had two lanes at the end waiting for a car to go. Usually, I'd wait till it's gone, but I've seen cars go through a two lane roundabout because the person coming through has their own lane. So I decided to go. However, I didn't realise the car was going straight and I thought they were turning, so in short, I could have hit them but didn't (just). Although no one beeped, but I think some guys from my school saw me, not sure if they recognised me. To make my day better, I was at a traffic light later on and hadn't noticed it was green so I got beeped at.

Felt really bad after this, and still do, so I thought I'd hear some of your stories, just to know it's not only me who makes silly accidents on the road.