In an interview about his new short story collection Between Friends, Amos Oz reveals his philosophy on happiness:
Happiness is a big word. Happiness as a human condition is something I never believed in. I think there are moments of happiness. I don’t think there is a lasting happiness. I think this is unthinkable. In the Jewish tradition we have no less than six Hebrew words for joy: “simcha,” “alitzut,” “chedva,” “tzahala”, but no proper word for happiness and perhaps rightly so. Joy is something that comes and goes. The idea of everlasting happiness is alien to me. I don’t believe in it.
The Dish 