system
Given the following post, respond as if you're commenting on Reddit:
human
[Supernatural] What is it about going to hell spiritually, that changes what you need physically.

Specifically why did Sam and Dean not even need sleep after returning from hell.
gpt
Dean required sleep like a normal person, he just had nightmares from the trauma, like PTSD. Sam was a special case because (spoilers) he returned without a soul, which is why he didn't need to sleep. Once he got his soul back he slept again.