The unforgettable piece from the Woody Allen's "Love and Death" movie (1975!):
Sonja (Deane Keaton): "To love is to suffer. To avoid suffering one must not love. But then one suffers from not loving. Therefore, to love is to suffer; not to love is to suffer; to suffer is to suffer. To be happy is to love. To be happy, then, is to suffer, but suffering makes one unhappy. Therefore, to be unhappy, one must love or love to suffer or suffer from too much happiness. I hope you're getting this down."
The must-see video: