I rarely use my horn and it's for that reason. I don't want some fool to brake check me out of spite. When I do use it, it's primarily a tap to "wake up" a driver who is seemingly obvious to his/her surroundings.
I try hard to never get upset or out of sorts while driving because I wouldn't want to do something stupid. Down here in the Rio Grande Valley, you may be the only one obeying the rules of the road. Most everyone here considers them to be "mere suggestions" at best. Everyday when we go out we are on frontage road for a bit. There is always some fool who turns left from the far right lane (3-4 lanes over), so we are always on the lookout.
Dale