Quote from : The Interpretation of Murder Book

There is no mystery to happiness. Unhappy men are all alike. Some wound they suffered long ago, some wish denied, some blow to pride, some kindling spark of love put out by scorn -- or worse, indifference -- cleaves to them, or they to it, and so they live each day within a shroud of yesterdays. The happy man dies not look back. He doesn't look ahead. He lives in the present.