Paulo Coelho said this quote

Oddly enough I never used to suffer from depression on cold, gray, cloudy days like this. I feel as if nature is in harmony with me, that it reflected my soul. On the other hand, when the sun appeared, the children would come out to play in the streets, and everyone was happy that it was such a lovely day, and then I would feel terrible, as if that display of exuberance in which i could not participate was somehow unfair.