I've shaved someone else once. Good friend of mine who was scared of it and I mostly wanted to show him its not nearly as bad as he thinks. Didn't touch the chin/upper lip area and only a 2 pass wtg everywhere else. Was deffinetly like learning how to shave again. Would be kind of cool to learn how to do it proficiently but like you said, no real use for the skill. For that reason I just let someone borrow a razor if they want to try. So many variables and its best if you figure out what you like for yourself I think.