The late, great Bob Engnath, who used to grind blades in his Glendale, CA shop, included this story in his catalog:
I had a guy spend some time at my counter one day, explaining how expert he was with the use of the Katana, or Japanese sword. He decided to show me the proper, chopping stroke, using one of my boldly curved, Tachi blades.. The ceiling was high enough, and there wasn't anyone else around, so I said he could demonstrate. This fellow tried an overhead stroke. With a tremendous yell, he swept the blade way back over his head in the backstroke. Then he let out another, different sort of yell. He'd wound up so far on the backstroke that the tip of the blade went about an inch and a half into the top of his right bun. Never did come back to show me how the rest of it went. Moral of the yarn. Anyone can do some Errol Flynn stuff with a button tipped foil, but when you're messing around with two and a half feet of sharp steel, you'd better know where it is, all the time.