It is not true that men never change; they change for the worse, as well as for the better. It is not true they are ungrateful; more often the benefactor rates his favors higher than their worth; and often too he does not allow for circumstances. If few men have the moral force to resist impulses, most men do carry within themselves the germs of virtues as well as of vices, of heroism as well as of cowardice. Such is human nature — education and circumstances do the rest.

Napoleon : In His Own Words (1916)