Most successes are unhappy. That's why they are successes - they have to reassure themselves about themselves by achieving something that the world will notice.
The suffering and calamity are, moreover, exceptional. They befall a conspicuous person. They are themselves of some striking kind. They are also, as a rule, unexpected, and contrasted with previous happiness or glory. A tale, for example, of a man slowly worn to death by disease, poverty, little cares, sordid vices, petty persecutions, however piteous or dreadful it might be, would not be tragic in the Shakespearean sense.
I do not perceive even one other thing, O monks, that when undeveloped and uncultivated entails such great suffering as the mind. The mind when undeveloped and uncultivated entails great suffering.
And, indeed, I will at this point ask an idle question on my own account: which is better — cheap happiness or exalted sufferings? Well, which is better?
Of all the ways we have found to hurt ourselves, the worse has been through love. We are always suffering because of someone who doesn't love us, or someone who has left us, or someone who won't leave us. If we are alone, it is because no one wants us.