I didn't exactly say he thought it was dumb... It's just easy to make fun of extreme hobbyists -- especially if they're friends. I think that was in the realm of good-natured ribbing. And for my benefit as the n00b in the room. Some of his customers are real sharpening nuts. And it is helpful to know certain theoretical limits even if you back off from them for practical purposes. 15k or 20k also for razors, for paper knives, etc. But you'll notice he specifically doesn't have those stones listed on the website. There's a video of the 15k Gesshin, but you "have to know".