User blog comment:ImperiexSeed/Castiel's shifting of Sam's mental problems made no sense!/@comment-4873164-20120403141655/@comment-3481504-20120404142902

No, it's exactly like that, money, food, etc. And no, the brain doesn't work after death, then it wouldn't really be death.

Now that makes sense, the body he's in sees them, i.e. Lucifer, and likely experiencing the very same problems Cas described in "Caged Heat".