Do you need sadness to know happiness?

[Matthead012]

I constantly wonder why sadness is a part of our existence whenever I have a bad day. Why do we need to be depressed? Even though I'm happy right now, I know that happiness won't last forever and will eventually give way to melancholy. Why is it that without grief, pleasure is impossible?

The explanation is that there is no such thing as eternal happiness. A necessary feeling that we can't turn off is sadness. In spite of being able to, we shouldn't desire to. In order to appreciate and be grateful for the happy times in our lives more, we need to experience grief in our lives.