I'm relatively new so please forgive my ignorance. I keep seeing the expression "smiling blade" and I am curious to what everyone is referring. I have an old Shefield blade that has an edge that is curved rather than flat and straight like most of my newer razors. Could that be the curve people are referring to? Is that the original blade shape on some razors or is it the result of use and poor or excessive honing? Mine is extremely sharp but I wonder what kind of shave it would be with the slightly curved blade.