Back in the beginning, there was a time when John still tried to pretend that he cared about things like healthy meals, dental hygiene, and steady bed times. Dean was old enough to remember that time in his life, and those values stuck with him, even if his father slowly let it all fall away.

They couldn't afford the dentist. And to be honest, even if they could, they barely ever stuck around in a town long enough to get an appointment if they'd need one.

So when Sammy slipped into the motel bathroom one evening, his footsteps muffled by his fleece footie-pyjamas, and sat down on the lid of the toilet, watching his big brother brush his teeth with a fascination unique to four-year-olds, Dean paused. Usually, after he'd finish brushing, he'd brush Sam's teeth too, and they'd go to bed. He watched Sam in the mirror for a few seconds, before frowning. He spit, rinsed with one of the two glass cups provided on the bathroom counter and turned, drying his mouth on his sleeve.

"You wanna learn how to brush your teeth by yourself, Sammy?" he asked.

Sam tilted his head, like he was thinking about it for a second, before he grinned, his perfect, tiny white teeth showing. He nodded.

Dean smiled and grabbed the trashcan next to the toilet. It was empty, and he turned it upside down so Sam could climb up on it and see himself in the mirror. Sam, for his part, looked far more excited than anyone should be at the prospect of brushing their own teeth. Dean shook his head.

"Okay, so I'm still gonna have to brush your teeth too, just to make sure we get it right, but you start. Here," Dean grabbed Sammy's toothbrush, and the Tom and Jerry toothpaste, squeezing a tiny pea-sized bit onto the bristles. Sam took it from him and stuck it in his mouth, frowning as he tried to maneuver it correctly.

"Here, let me help," Dean said, reaching for the end of the brush. Sam pulled away.

"No, Dean, I want to do it!" he said, the words messy and distorted around the toothbrush. Dean laughed.

"Okay, okay!" he said, holding his hand up. "I won't butt in if you don't want me to, I'm just trying to help." Dean watched in silence as Sammy tried a few more times to twist the toothbrush the right way. He caught Sammy sending him little glances in the mirror every few seconds. He was clearly getting frustrated.

"Do you want me to just help you move your hand the right way and then I'll let go and you can do the rest?"

Sam paused, looking hilariously suspicious for a second, before he finally nodded. Dean stepped up next to him, taking his right hand and uncurling the grip Sam had on the brush. He adjusted it, and closed his fingers over the end again, holding Sammy's little fist in his hand as he raised it to his little brother's mouth.

"Okay, open up."

Sammy opened his mouth and Dean helped him start to brush along the bottom of his teeth in the back. He let go after a second.

"Like that, okay? Make sure you keep the brush part on your teeth, and just keep moving around. Each new spot you start brushing, count to twenty. You can do that, right?"

Sammy nodded, mouth hanging open and a look of intense concentration on his face.

Sam followed Dean's directions, working his way across the bottom row of his teeth and then the top. Dean had to help him fix his grip a couple more times, but Sammy let him.

After Sammy was finished, he let Dean brush his teeth a second time, and then Dean helped him rinse and spit.

"K, now remember. This is important. You listening, Sammy?"

Sam nodded, climbing down from the trashcan.

"You have to brush your teeth every day, you hear? Morning and night. You can't forget, 'cause it's not good for you and we can't really go to the dentist. Even if I'm not here, you still gotta brush, k?"

Sam nodded. "But Dean, where are you gonna go?"

Dean laughed and ruffled his little brother's hair. "I'm not going anywhere. I'm only sayin', you know, just in case." He shrugged. "Anyway, c'mon, bed. Dad should be home soon, and he said he wanted you to be asleep when he got back."

Sammy followed Dean into the motel room and Dean tucked him in before lying down next to him, and pulling out a comic book.

Honestly, Dean was the reason neither of them ever got a cavity, despite the amount of junk food they both ate.

When Dean went to hell, most of Sam's life went to hell too. A lot of things got ignored and forgotten. He got a bad cut on one hunt that he left so long it got infected. He skipped sleep, bags forming under his eyes, and he forgot to eat, sometimes for over 24 hours. He got sick that summer, high fever, weakness, sore throat. He just pushed on, ignoring the dizzy spells and pain.

But he brushed his teeth every morning and every night, counting to twenty in his head each time he shifted the toothbrush.