On sharpening knives, when I was about ten years old, my dad bought two carving knives, one was quite broad and the other around 2/3" wide all along.I remember him telling me that they were very special because they were 'hollow ground'! He explained the theory very well, and I suppose I never forgot it. My sister said it was a special 'pork knife'.
But I could never understand what happened to the 'hollow' bit after being sharpened for ages on a stone, as of course, it wore down! Dad could carve pretty well, and I also like carving so I suppose it's something I learned from way back.
When we cleared the house, we found the same old knife and it was about 1/2" wide but still incredibly sharp, but as for being 'hollow ground' - well, it just wasn't...