Oh yeah, great one. I love knots. When I don’t have a technical puzzle to mull over while drifting off to sleep I like to visualise knots - it’s surprisingly tricky to follow along without a line in your hand.
Everyone should learn the bowline because it gives you a lot of bang for buck. One I discovered on the brilliant website below that I’ve really come to love is the tumble hitch (quick release hitch on a bight).