At "morning coffee" one day in November of 1979, I taught a shy PhD student how to play backgammon. That was a daring thing to do in the University of Cambridge maths department, due to the notorious kibitzers. The PhD student was glad that I asked him to play, since no one else even had the patience to explain the rules to him. Topologist Frank Adams came over to chat with us while we played, which was a friendly thing to do. Adams was in a good mood because he was pleased with the deck transformations story he had told in class that morning, which he seemed to be especially fond of because it was an anti-American joke. We got off easy on the kibitzing that day.
A few days later, we experienced the Attack of the Kibitzers. There weren't too many people at afternoon tea (at first), so the backgammon set wasn't in use, which was a rare occurrence. To avoid one of the grad students who was hitting on me, I asked the shy PhD student if he wanted to try backgammon again.
It started peacefully enough, until John Conway sat down and told us what moves to make, using specialized language we didn't know. He spoke much too fast for us to think it through, and he moved the pieces himself if we didn't react quickly enough.
When it was all over, Conway turned to me and asked, "Now wasn't that fun?"
Everyone laughed (including, and especially, me), because all I had done was roll the dice. I felt sorry for the PhD student since it was only the second time he'd played, but he took it well.
Next, two of the grad students played, and were met with the same treatment. But to thwart Conway, one of them decided to play a variant of the game in which he purposely went against Conway's advice, even if Conway told him the only good move, which he had already seen for himself.
After that, before I ventured to play backgammon I was careful to see who was around, and then decided whether I had the fortitude to stand up to their "suggestions".