People Who Don't Know They're Dead

Came across this link over at Reality Carnival:
"When people die by accident, in violence, or maybe they're drunk, stoned, or angry, they get freeze-framed. Even if they die naturally but have no clue what to expect, they might not notice they're dead. It's frustrating to see and not be seen. It's frustrating to not know what you're supposed to do next. It's especially frustrating to be in someone else's body and think it's your own. That's if you're dead. If you're alive and that spirit has attached itself to you, well that's a whole other set of frustrations."

Are there insane asylums in the afterlife? A lot of those spirits sound sorta bonkers, in my estimation.