HOW ABOUT A QUICK WAVE, JACK-ASS?

I don't get it. When I'm driving in my car and someone let's me go ahead of them, I give a little wave to say "thank you." It's effortless.
When I let someone go ahead of me, I never get a thank you, or a nod, or even a smile.
It makes me want to SHOVE A STEEL POLE UP THEIR ASS.