If Jim's feeling humorous, he'll go into each and every symptom he has or ever had since 1988. He will go on and on until even I am flustered!

Most people will not walk away because they feel obligated to stay since they asked. It definitely stops them from asking again.
He does this to telemarketers too. He once testified to a telemarketer for over an hour and had the whole office on speaker phone listening. That was pretty cool to watch. They never did call back.