I got in something close to a "real" fight today, something that happens to me somewhere between very rarely and almost never. The story starts with me walking down the street in Downtown Portland, Oregon, carrying a bag of groceries on my head, which is how I always carry my groceries. This usually gets some reaction from a few people, mostly complimentary. Today, someone said "nice hat" which is a common enough joke, and then tried to push it off my head. I caught them and turned around very quickly, getting into a fighting stance and probably cursing. (If you are ever in one of these situations, you will find that your memory of what exactly happens and what was said becomes very blurry quickly). The friends of the young man, (who was probably in his early 20s) apologized for his drunkenness. I also apologized for overreacting, but tried to get in a word about what happens when you attack people walking down the streets.
I am glad to see that I react very quickly to a perceived threat, with what seemed to be just the right amount of anger.
Even though I don't actually know the person's life story, as such, I am still going to make some guesses. My own experience of living in the city is that people in the city are fairly polite, but there are some suburban youth who have seen too much television, and feel that once they go downtown, they are in CYBERPUNK DRUNKEN NIHILIST ORGY land, and can get away with anything. Of course, once they slink back to Beaverton, they will probably have to be polite for their parents and their boss at the grocery store. That is speculation, but I think it might have been the case in this case.