What is wrong with some people?

I had the opportunity to teach someone basic manners yesterday morning.
I walked down the train platform to get on my preferred carriage and I thought that there was no-one left to disembark. Then I saw him—a dishevelled looking man of about 45 clutching a timetable or a map, about to get off. So I did what any decent person would do: instead of pushing past him to get on the train, I retreated a few spaces and stood well out of his way.
But, alas, he did what most people seem to do these days when you hold a door open for them or provide them with any other small courtesy: he completely ignored it.
So I sardonically told him, "You're welcome!"
He shot me a quick but nasty glance and mumbled something that was probably along the lines of "Piss off" or "Go Get Fucked."
"What's that?" I said. He didn't answer. He glared at me again.
So I stood in the carriage doorway and glared at him, and my stare told him that I meant business. He looked at me for perhaps just a second or two longer and walked off, not saying a word. He just walked away.
That's one confrontation that I won, hands-down. I stared the bastard down. I'm not proud to admit this, but it made my day. I don't like to fight, hardly ever do, and will go some reasonable length to avoid it. But when I'm charged up, I don't pull any punches.
I said it all with my stare. That look of pure poison that I bore down on him with told him, "If you don't back the fuck off right now, you're gonna get a pummelling." I didn't expect him to apologize—the time for that had passed. I just wanted him to have no doubts as to how serious a challenge I considered this if he didn't stop glowering at me and that I would rise to the occasion if he didn't.
Was I in the wrong? Am I just too angry a person, looking for any excuse to have a go at someone? Or, was I right to call this guy out?
As I say, he looked at bit dishevelled or disoriented. He had been clutching what looked like a map of the train system. Should I have just forgiven him for what was undoubtedly a bad morning on his part?
But consider this, dear reader: I may be high-strung and have a considerable temper. But—but—I still say "please" and "thank you" to people, no matter how good or bad I'm feeling. I never ignore people when they do me a courtesy. In fact, that sort of thing helps cheer me up if I'm hot under the collar. If I'd had a rough morning, and someone had stood aside while waiting for me to exit the train, I'd have acknowledged it. I would have said thanks. Sure, I might have mumbled it, but I'd've said it all the same. And that's all I wanted. Just a mumble. A positive grunt. Something.
What I didn't expect was some piss-poor attitude that would suggest, "well, of course you got out of my way, you little peon. What do you want, a medal for it?"
And that's the sort of behavior that I am not going to stand for. I simply won't tolerate it.
I just hope the next time someone holds a door open for him or stands out of his way when they see him coming, he does the gentlemanly thing.
Because, as far as I'm concerned, there's a very fine line separating a gentleman from a blinding-and-effing rage.