Quick little story built from prompts from Nova42: water, and the line "It's not a tired you can sleep away."
Set sometime early in the series, probably Season 1.
Driver Picks the Music
They say you'll never forget how to ride a bike, and Sam Winchester will never forget how to assemble a Smith & Wesson 4006.
The things he forgot are less tangible. Not the weapons or hand signals or Morse code, but how quickly he goes through clean clothes, or how TIRED he is, all the time.
He's been tired before, recently. Typical tired, overachieving-college-student tired. Pulled all-nighters studying for exams, but you take the test at 9AM and go directly to bed without passing 'Go' or collecting two hundred dollars. You press reset and start fresh the next day.
This isn't a tired that can be slept away. Spending any stretch of time in this life demands a permanent change to your make-up. This is an ever-creeping, bone and world-weary state of exhaustion that can never be completely driven away, but can be held at bay by chasing adrenaline and consuming unhealthy amounts of caffeine that would send anyone else into cardiac arrest. It's all a temporary, mostly inefficient fix.
He forgot the non-routine routine of it all. The inconsistent sleep schedule that guarantees he'll never feel fully rested, the sheer number of hours spent in a car that's been eating asphalt for so long she probably shouldn't still be running. The dive bars and seedy motels, sticking to shadows, and blood everywhere.
He forgot about the food. Cheap, convenient, caloric. Dean eats like crap, constructing meals from a food pyramid built on protein and carbs alone, and he doesn't drink nearly as much water as he should, substituting this necessary hydration with sugary energy drinks, strong coffee, and an overabundance of alcoholic beverages. He scoffs when Sam picks up a bottle of water at every gas station, double-fists Red Bulls and then plays a jittery drum solo on the Impala's steering wheel.
The problem with Dean is he doesn't ever leave the door open for conversation, and he almost always has a weapon of some kind in hand. Something about sunlight bouncing off of the freshly polished nickel-plating of a Desert Eagle doesn't scream, let's have a serious conversation about my health and wellbeing.
Sam has to do it quick, like pulling off a Band-Aid. "Here."
"What's that?"
"Water?"
Dean sighs, annoyed. He pulls back the slide on the pistol, and Sam feel a bit validated in his hesitance. "Why's it in my face?"
"So you can drink it."
"So now you're in charge of how fast I drive, AND what I eat and drink?" He takes a long pull from the beer bottle on the side table to punctuate his words. "I know you've been out of the game a while, Sammy, but as little brother you've only got one responsibility. Do whatever I say."
Shit rolls downhill, Sam muses. Shotgun shuts his cakehole, he remembers. "I've never said anything about how fast you drive."
"Oh, please, I see you over there all the time putting on the brake like a friggin' driver's ed instructor."
Sam swallows a retort, sets the glass aside.
Dean nods approvingly, finishes up with the Eagle and sets her in the line. "You want dinner?"
"Sure, but I'm picking this time."
"What? Why?"
"Because I'd like to eat something I don't have to squeeze a gallon of grease out of. When's the last time you had a piece of fruit, Dean?"
Dean opens his mouth to argue, then cocks his head. "Huh. Touché, Sammy." He slaps his thighs. "Okay. You pick."
Sam doesn't think he's ever enjoyed a Caesar salad so damn much in his life.
"Hey, Sammy."
He looks up from a plate of lightly dressed romaine to see Dean drag a slice of tomato from the depths of his cheeseburger.
"S'a fruit, right?" Dean takes a dramatically large bite from the juicy red slice. "Take that, College Boy."