Last time someone honked "at me" was right after I had gone through a cloud of dust blown up be 'gardeners' with leaf blowers. I was pissed off already as it was both nasty and dangerous (the cloud of dust).

I turned and cussed out the car. They passed me slowly and the passenger politely told me that they were honking at the jerks making the cloud, not me and that I was fine as far as they were concerend.

Hopefully in the future I'll take a little longer to be sure just who the horn is aimed at.