Dean pumps the gas for the Impala, Sam grabs a bag of peanuts, two bags of twizlers and a bottle of coke.
Dean gets the bed closest to the door, Sam always lays the salt lines.
Dean keeps away the bullies, Sam does the dishes.
When Sam gets scared he goes to sleep with Dean, when Dean gets scared Sam feels it from across the room and just opens his sheets in a silent offer.
Dean cooks lunches and breakfasts, but Sam gets clean up and dinner.
Dean protects Sam from zombies and ghosts, Sam protects Dean from teachers.
Dean doesn't die, Sam doesn't leave.
They never really talk about anything. Not about being alone so much, or always being on the move, or even their day jobs. But that doesn't mean they don't' deal with it.
When it gets to much they just stop and take a breath. For Dean rationalizing their life is as simple as just staring at his brother and knowing in any other life he wouldn't get to be with his brother 24/7.
For Sam it's just a matter of curling himself into his brothers' arms and having that fiercely protected feeling wash over him.
Then everything goes back to normal.
Dean gets the gas, Sam gets the snacks.
It's their way of life.