This will just get buried unfortunately, but I've actually thought about this and how it's probably less foreign to people than they think. You ever lose someone really close to you where it sends you into a total tailspin? You don't feel like doing anything, you don't even really see the point in talking to anyone about it. Your thoughts are 100% negative because you've been reminded that there really is no point in caring about things when it can all be taken away at anytime.

Then a couple weeks pass and the fog starts to lift and in due time you're right back to normal, your hobbies pick back up, you start talking again, etc. I figure this is an experience many people unfortunately know. Well imagine nothing even had to happen to set it off and the fog doesn't progressively lift-- and you've got depression. Yea, it's quite literally the worst.