Sometimes I think it is a simple involuntary reaction. Like a diarrhea of the mouth thing. You interact with a stranger and suddenly what they expect to happen doesn't. They have a person standing in front of them possibly contorting their face saying, "W-w-w-w-w-w....". In shock they may laugh, or look at you like you are an alien. It still hurts, but I can understand why that happens and why they react that way, it is unusual behavior. We have to give folks like that a little slack. We've put them in a situation they weren't prepared for. Those who know that what you are dealing with is not in your control and still choose to attack you are a different story. They need throat punched.