As a rule, I think they are quite impossible. Geniuses talk so much, don't they? Such a bad habit! And they are always thinking about themselves, when I want them to be thinking about me.
For, though the origin of most of our words is forgotten, each word was at first a stroke of genius, and obtained currency, because for the moment it symbolized the world to the first speaker and to the hearer. The etymologist finds the deadest word to have been once a brilliant picture.