Lol, I learned right off when I was learning how to really use my stones and strops to always have the Band-Aid can right there in easy reach. Some of my Japanese Knife blades are 240 mm long. That's a lot of edge to sharpen and with the tip of the fingers right at the knife's edge, things can happen if your mind is somewhere else. Oh yes, the bottom of a coffee cup or bowl can hone a knife real good to bring back the edge to sharp. Often times , from just using the knife and hitting the board to hard can roll the edge or put micro chips in the apex of the knife. Running the edge across the bowl or cup will sometimes remove the burrs that were formed by hard use. I always strop before I take my knives to the stone. Saves steel and stone.