For years I have felt sad without knowing the reason. Some nights, I'd feel very bad. A feeling of missing something essential, though I wouldn't be able to pinpoint a thing that I miss. I'd sometimes discover something as the cause for my worries. Once such a discovery has happened, I can then consciously think about that and worry deeply. It has never helped much.
Only a few weeks ago I found out that I don't know the reason for my worries because there's no real reason. Because I was never worried. I was only feeling tired and/or sleepy. Just letting myself relax and rest would bring my happiness back. Mind is a wretched thing that rejoices in its own tears!