Why Did Napoleon Call Power His Mistress?

David Senra reads Napoleon's line in The Mind of Napoleon that power was his mistress. Napoleon had worked too hard at her conquest to allow anyone to take her away. The cost named in the book is the sufferings, the sleepless nights, and the scheming.

In the same stretch, conquest made him what he was, and conquest alone could keep him there. Power depended on glory, and glory on victories, so that power would fall without still more glory and still more victories. He was not master of his actions, because it was insane to try to bend events to fit his policies. He bent the policies to the unforeseen shape of events instead. As soon as he ceased to be feared, the empire would be destroyed. From triumph to fall, there is but one step.