"Good evening po," I said. "Good evening sir," he greeted back.
It's in the good human being code - to be nice and polite to everyone and to not be a burden to anyone. But if you're an Uber rider, you go the extra mile for the stars. Five stars, no less. A couple of fours would drag your rating down, and some threes could easily relegate you to the circle of the riders from hell who deserve being ignored, rejected or cancelled.