Life is too short to lose your cool on some trivial matter (even though at the moment of red mist, that matter is a BIG issue to you).
Speaking from experience, I nearly lost it many years ago when a car behind horned me like there was no tomorrow because I cut into his lane. Actually, I was not at fault. I signalled, changed lanes gradually, with the car still far behind me. I guessed he didn't like slowing down for me. Well, I saw RED MIST that time. Just suffice to say here that I nearly drove right into his car at high speed (actually, I did scrape a little paint of his) -- but managed to control myself in time. That driver was so cowed after that. But I didn't gloat because I knew it I had completed what I intended to do, I would have probably cause some bad injuries and probably have to visit a criminal court.
Now, at traffic stops, for example, if I see an unalert driver in front, I would often give a short beep on my horn (like "beep" rather than like "beeeeeeeeeeeeeeeeeeeep"). I believe car horns can reflect or express a driver's emotion. Short beep usually means a friendly reminder/alert/warn. But a long beeeeeeeep often reflects anger, impatience, or mockery. People react differently to both these types of horning.
Chris
I'm totally agreed on this.