They go through this character development/realization when they're ghosts, but as soon as they wake up from their sleep/coma, they don't remember any of it so nothing really changed and they remain the same as they were before the surgery. So what is the point of Charlie even helping them? What a waste of time.
🎎
They may not remember their time in limbo, but a lot of them retain a bit of what they had to learn.
A few examples:
Maggie knows she has to focus on herself for once.
Katie was willing to let her son with Down syndrome be independent and take care of her.
Alison the nun actually remembered her moment and took it as a sign she was on the right path.
If they don't remember, he does and gives them a subtle reminder or tip when they wake up. Or sometimes they are simply there so Charlie can diagnose them and save their life. He's learned something for himself a handful of times too.
Best element of the show IMO.
Milo, I've told you again and again - please, don't walk on the chickens!