hollow chocolate bunny o the apocalypse

Hypothetical situation:
You do something nice for someone like hold open the door, pick up what he/she dropped, or make sure the bus doesn't leave without them.
He/she does not thank you.

What do you do?

The most common response thus far is the loud, sarcastic, "You're welcome!" response. I'm not of this school of thought. Sure, it would be nice if they thanked you. It's only polite. But is that really why you did the good deed? In my ever so humble opinion, shaming them into thanking you kinda negates the good deed. (Unless it's a small child to whom you are trying to teach manners (ie drill please and thank you into their little pea brain so that they don't become ungrateful little punks.))

Today I was walking to catch the bus when it started to pull away from the curb. I started to run and someone at the stop flagged down the bus driver to wait. As I ran past this good samaritan I gasped "Thanks." He acknowledged this with a rather forceful "You're welcome." This and his next statment "You could have said thank you!" tipped me off to the possibility that he hadn't heard me. I became angry. Suddenly, this man had been transformed into my eyes from a nice guy who I was grateful to, to a whiny litle bitch.

Thoughts:
I guess he thought I was an ungrateful little bitch so perhaps we're even.
If I was chronically impolite, would I care if someone rudely answered "You're welcome!"?
Would I even notice their tone?

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To J: Hitting on my friends? Smoooooth.