Usually, he can assume the age he looks, sink into the bones and flesh of this too-young body and pretend--even to himself--that he’s nothing more than what he seems, that time still holds sway over him, that he hasn’t lived a lifetime past what's written into his skin.
He looks thirty-five, and he is, more or less. He could work out his exact age if he bothered to do the math, but measuring the time he’s spent on earth seems kind of pointless these days. Sam didn’t get that the first time around, but after the Cage, he’s caught on.
(sometimes Dean looks at Sam and he doesn’t see his baby brother, the too-tall, too-tired, tough soldier kid that he’s managed to raise; sometimes he looks at Sam and all he can see is Hell, decades of it, a whole goddamn century of it, and he wonders if cutting Sam’s throat while he sleeps wouldn’t be the kinder option after all.
and he doesn’t do it, he can’t do it, but he doesn’t know if that’s sanity or selfishness)
They don’t celebrate birthdays anymore.