Why? The question is...

There's a certain someone who's constantly asking me questions that he already knows the answer to. He asked me the other day if so-and-so was from Bombay. Now since, Bombayites or Mumbaiites as they are called today, never really have a standard look, dress sense, way of talking or special mark tattooed across their forehead, it's pretty obvious that "annoying question asker" already knew that so-and-so WAS from Bombay. Why he was cross checking this petty, insignificant, little detail with me is beyond my comprehension. To quote a song from Peter Rabbit..."Why does he do it, what is the cause?" It isn't the first time.