To be fair... I don’t know how well Buffy teaches that lesson, unless there is a what not to do there.

I think my current theory, and the only way I can really make sense of the end of the fight is that Rey is Luke’s daughter. But prior to Kylo’s fall, Luke and the mother had a break in their relationship. She leaves him and takes her daughter (perhaps they broke up over his decision to train Jedi? It would make sense…