It is not funny that anything else should fall down; only that a man should fall down... Why do we laugh? Because it is a grave religious matter: it is the Fall of Man. Only man can be absurd: for only man can be dignified.
Men always talk about the most important things to perfect strangers. In the perfect stranger we perceive man himself; the image of a God is not disguised by resemblances to an uncle or doubts of wisdom of a mustache.