Losing your temper when a serious boundary has been crossed is natural and expected. It had a positive outcome in that it stopped your bad behaviour immediately.

> He ended up grabbing me by the throat, while no-one around did a thing to stop him.

The bystander effect is real, but you should also take this opportunity for self-reflection, because in this case, you were the person behaving badly who instigated the situation.

> But I doubt I’ll learn anything from it

Yes, unfortunately it seems unlikely you will.

Serious boundary? He put tits in front of my eyes. Am I supposed to remember to keep my eyes pinned to the floor when out in public? What a terrible way you must live.

I’m afraid to say, that if you want a boundary, go home. Otherwise, accept that you’re in public, and people can and will speak to you.

Also, you’ve just justified being violent in response to someone making sounds with their mouth. I bet you’re a calm person to be around, when everyone does what you want.

No verbal comment, be it a comment or an actual insult or otherwise, justifies violence and crossing the body threshold. In what world do you live?