A stunningly inappropriate and thoughtless question often blurted toward a handicapped person, the only proper answer to which is "Don't ask".
"What happened to you?" asked the seemingly civilized man of the woman who was struggling mightily to take each halting step. Yet she needed no reminder of how hard it was to move, or of how many years she had been in pain. She was under no obligation to answer the moronic stranger, who in any event seemed to want no answer and quickly began prattling about his skiing accident, years ago, which he believed would be fascinating to a woman with a permanent handicap, but, please... don't ask.