My late littlest brother could sharpen things -- knives, axes, wedges, whatever.

One time he came visiting and offered to sharpen the knives. He did, and I asked him to sharpen the knife blade on my Leatherman multi-toom. He did, and said it was good enough. Inquiring what he meant he said that he never sharpened anything as well as he could because it would be "dangerous."

Of course, I convinced him to go all the way. It took some talking, but he brought the blade up what he called "dangerous."

A week later I was standing at the counter in a hardware store (ironmonger's shop) and took out the tool to cut something. Before you knew it I was bleeding all over the counter. Just a bad cut and the store had a first aid kit, but my brother certainly did say, "I told you so."