Winter depression

Is it extremely Common for depressive episodes to just hit like flashbangs?

Not ate a single thing, slept 8–9 hours and still fighting the urge to just fall asleep in class.

I was a chronic marijuana smoker before my first major depressive episode hit me last year, so I didn’t notice the transition at all back then

but damn… is it really just normal for you to just lose your appetite one day and just become mad tired for the following days? Been wanting to delete my music cant even be bothered to meet anybody either.

Wondering because I thought that depression was a thing that gradually just kinda crept up.