Dean doesn’t know how Sam stood up to John for him when he was in the hospital dying after the car crash. Those memories of Sam staying by his unconscious body or bringing the Ouija board to talk to him were wiped clean when he woke up.
Dean doesn’t know how long and hard Sam searched in those 6 months tracking the Trickster. Or how he finally broke down and just begged for the Trickster to give him his brother back at the end of all those Tuesdays.
Dean doesn’t know how Sam gave up a chance to say safe inside his unconscious and numb the pain of Hell because he couldn’t leave him out there on his own. Sam did this even though he still thinks it was Dean who left him that voicemail calling him a freak and a monster.