During a BFR many years ago, I decided to use my aerobatic instructor. He was the last instructor I had used, so he was very familiar with me. We decided to do the flying portion first, in his Extra, and it was awesome. He praised my flying and went on an on about it as we walked to the terminal. I was on cloud 9.
Then it was time for the ground portion. For some reason, his attitude changed and it got ugly. No answer I gave was good enough and he was visibly angry. I finally snapped and told him screw it, I would find another instructor and do this all over again without him and I left. He followed me outside and acted like he didn't know why I was upset. He signed my BFR and we never spoke again. Now that I'm older, I wouldn't even tolerate as much as I did that day. Not worth my time.