One libretto from Cherubini's Médée
Médée
O cris plus doux pour moi que deschants d'allégresse!
Medea
Oh, for me the cries are sweeter than songs of joy!
Sometimes, I quite enjoy with this sadness. I will be more clear-minded than being happy and joyful. Happy and joyful feeling will always make me in a dangerous state. Sadness requires me to find out solution and keep me looking forward.
I always tell people that having a short time of sadness is quite enjoyable but you need to stop it after a certain time. Otherwise, you will fall and fall until the bottom of the hell. But there are not many people can do this. Most of them will be sad all the time or pretend to be happy, however, they still can't recover. The more they being sad, the more painful they are, unless you can control it.
Good Luck!