They don't need her.

That's the hardest part to accept, harder than the fact that she had been dead more that thirty years, to come back and find that the babies she left behind are older than she is now, that there are hundreds of tv channels, that phones have built in computers and literally everyone carries one in their pocket, that Russia doesn't want to blow us up anymore, or that the Rolling Stones are still touring.

Two days ago, she had babies. Sam was just starting to eat rice cereal and pureed bananas. Dean tried so hard to be a big boy, but he still ran straight to mama when he scraped his knee or got scared. John could listen to someone's car over the phone and tell you what was wrong with it, but he couldn't find his good tie hanging in the closet if his life depended on it.

She had been so afraid to face Sam, knowing that she had made a deal with Yellow Eyes to get John back, that it was her fault he had been infected with demon blood, that he knew she was to blame for his fiance's death, that it was her fault that he had grown up as a hunter, without a mom.

Except, she realized as she saw Dean gently examine each and every one of Sam's wounds, stroke his hands over Sam's face, whispering that it was over and Sam was safe, and then demand that the angel heal Sam (and her, of course), that Sam did have a mom.

Sam had a mom, and it wasn't her.

Sam's eyes kept flickering over to her, but Dean was the center of his attention.

His wonder that Dean was alive and had come for him was amazing. Her boys were devoted to one another.

It also twisted the knife in her heart just a little further.

She was intruding on a world where she wasn't needed. If there was any doubt of that, it vanished while Sam was in the shower, when Dean ordered Sam's food (Grilled chicken, honey mustard on the side) as certainly and knowledgeably as she would have ordered for Dean a few days ago.

She had been Dean and Sammy's mommy, but she wasn't Sam and Dean's mom. Her own children were strangers to her. They were grown men, and she had missed their entire childhoods. She found bits and pieces in John's journal, the story of Sam's first steps or Dean's first day of school. Those were only crumbs, tidbits that left her desperate for more, in a way the boys who had been together almost always could not imagine. They had a best friend who was an angel and talked about people named Jody and Bobby and Pastor Jim that she had never heard of.

She had been with John only a few days ago. To them, their father had been dead so long that the grief had softened into reminiscence, to stories of their dad bringing soft smiles rather than sharp emotions. Meanwhile, she was barely holding together at the mention of his name.

She had been dead to them even longer, so much so that while they were thrilled that she was there, their entire lives had been built without her. Sam didn't remember her at all, and Dean's preschool memories seemed exaggerated.

They didn't need her, and John wasn't there to need her any more.

She tried hunting, to see if saving people and hunting things made her feel useful.

It didn't.

It showed her the fact that the boys had been hunting together so long that they worked in perfect synchronicity, knowing exactly what each other was going to do before the other one did it, and that she was not a part of that dynamic.

They were her boys, and she wanted to love them, but she didn't know how. Not when she didn't even know who they were. Not when she didn't know who she was.

She had made difficult decisions before, but nothing like the decision she made after returning from the hunt.

She had to figure out who Mary Campbell Winchester was if she wasn't John's wife, if she wasn't Dean and Sammy's mommy, if she wasn't a hunter. She had to get her head around her new reality before she could figure out how her sons fit into it.

She only hoped that they would forgive her again.