Lost a pupil a few months ago after three 1½ hour lessons, because she didn't like my style of instructing.
Second lesson I wasted too much time giving her too much information.
Third lesson, I didn't give her enough information so she informed me she would be moving to another instructor. Adding, "would you be offended if I came back to you if I didn't like them?"
I didn't answer because I thought it was a joke. Yesterday my wife got a call from her wanting to book a block of 10 hrs. Needless to say I have a full diary!