A man has no business to be depressed by a disappointment, anyway; he ought to make up his mind to get even.
 Mark Twain, A Connecticut Yankee in King Arthur's Court (1889). copy citation

Context

“If I should find this well dry and no explanation of it, I could astonish these people most nobly by having a person of no especial value drop a dynamite bomb into it. It was my idea to appoint Merlin. However, it was plain that there was no occasion for the bomb. One cannot have everything the way he would like it. A man has no business to be depressed by a disappointment, anyway; he ought to make up his mind to get even. That is what I did. I said to myself, I am in no hurry, I can wait; that bomb will come good yet. And it did, too. When I was above ground again, I turned out the monks, and let down a fish-line; the well was a hundred and fifty feet deep, and there was forty-one feet of water in it.” source