i do not obsess over this, but when i use knives i always imagine horrid things- and yes i have cut the bejesus out of my fingers.... but i imagine slicing down the middle of my tongue with a knife...
i do not know why- it is just one of those thoughts and mental images that pops in my head when i am handling knives.... i have had this thought since i was little, i clench my fists when i think of it (instead of grinding my teeth)