Another pain-related plot bunny...
Ok, this bunny has been nibbling at my ankles since the last scene in 4.22 where we see Sam's face looking in at Dean, Lisa and Ben. It's continued to get worse now that we're in Season 6.
What if Sam came back from hell and for whatever reason (emotional/physical/?) he is now incapable of feeling pain?
There is actually a genetic disease where the sufferers grow up without the ability to feel pain. It leads to a lot of problems with accidental injuries occuring and worsening because there's no warning of pain to stop/avoid the dangerous behavior.
If that's what happens to normal kids, imagine the dangers of hunting without being able to feel pain.
What if Sam came back from hell and for whatever reason (emotional/physical/?) he is now incapable of feeling pain?
There is actually a genetic disease where the sufferers grow up without the ability to feel pain. It leads to a lot of problems with accidental injuries occuring and worsening because there's no warning of pain to stop/avoid the dangerous behavior.
If that's what happens to normal kids, imagine the dangers of hunting without being able to feel pain.