A knight remembers another banquet he had
"Oh, that was another really nice banquet; all the liars and the knights of the kingdom were there, even the village fool. We all ate and drank and at the end of it, the king asked each one of us to make a few statements about a few other people, meaning, to say if they are liars or knights. The same number of statements were said about each one of us, and each one made the same statements that the one before him made. I just don't remember what the village fool said this time.
"That's ok", you say, "you can know what he said even without trying to remember it."
How can he do that?