Fishing Knots. This is the one skill that just may save your life one day. Don't put it off. Learn them and do them every day(while you can) for several months, so it's in your muscle memory and you don't forget them. You can't trust that someone else is going to help you or save you ; when you need them to.
Fishing Knots | How to Tie Fishing Knots | Animated Fishing Knots