"For many years, three Jewish friends meet daily in Tel Aviv for coffee. Over the years, they become more and more pessimistic about the situation in Israel, noticing the increase in terrorism, poor economic performance and a reduction in the number of tourists. One day, one of them announces that he has converted. 'What?' the other two exclaim. 'Yes,' he says. 'I've converted from being a pessimist to an optimist.' A few minutes later one of the pessimists turns to the newly converted optimist and says to him, 'If you have become an optimist, why do you still look so worried?' 'Ah,' his friend replies, 'do you think it's easy being an optimist?' "
What Do Jews Believe? The Customs and Culture of Modern Judaism
Edward Kessler's parable on the paradoxical nature of optimism, or hope.