if you got little sleep in life, you'd probably be the most pissed off ghost, amirite?

Everyone should become a ghost before dying

Probably a relatively young pissed off ghost with limited realization of self and/or dementia.

Imagine you become a ghost because you are unwilling or unable to reincarnate and lose your "self" (you know..if any of that is real anyways). Thinking you can finally get some rest... And it's just ... Awake for eternity..