Taken Off Guard

Surely what a man does when he is taken off his guard is the best evidence for what sort of man he is. If there are rats in a cellar, you are most likely to see them if you go in very suddenly. But the suddenness does not create the rats; it only prevents them from hiding. In the same way, the suddenness of the provocation does not make me ill-tempered; it only shows me what an ill-tempered man I am.

C. S. Lewis