This morning some driver rushing to work honked at me. Again. At least that's what I thought momentarily. It turned out that she (yes, it was a woman) was not beeping at me but was trying to persuade another driver, in front of her and directly behind me, to pass me. That driver behind me was just waiting for a convenient moment to do it, since there were some cars approaching from the opposite direction. But in that woman's opinion there must have been enough space for passing me. Maybe there was, but not enough to keep the required 3-feet distance.
Something similar happened to me once when I was driving a car. The road was relatively empty with a car behind me. I noticed another car trying to merge with the traffic from my right and I decided to stop to let him go. Immediately, I got a loud honk from the guy behind me, like he was trying to say "You idiot, why are you stopping?". No, I did not stop violently and that car was not driving too close to me. I was just trying to be nice and let another driver to merge with traffic.
Why are people so aggressive when they drive? Honking is mostly rude and is not going to get you anywhere. Just slow down. Relax. You will get there where you want. This is another advantage of riding a bicycle to work. Ever seen an aggressive cyclist on a way to his office? Me neither.