He'd expected the students to be the worst part of reentering the world of academia, but his courses are advanced enough that they're mostly not complete idiots, and the university gives him TAs so he doesn't have to do all the grading by himself. The kids even wind up being useful after a fashion--helping him test theories and equations for the great Fix Everything project, even though they just think it's a wacky hypothetical, the astrophysics equivalent of the Kobayashi Maru.
His so-called colleagues, on the other hand, are largely a bunch of small-minded idiots, obsessed with titles and publishing and tenure. The battles fought over office assignments make some of the actual battles Rodney's participated in look tame by comparison. The pettiness of it all would be maddening, if he hadn't made clear from the very start that he had no interest in any of it. They give him an office that used to be the end of a hallway, which imitates the Sahara in wintertime and Siberia in summer; he's dealt with worse.
He's glad whenever Jeannie visits, and more glad when she leaves, although it does sting a little when even she gives up on him 'rejoining reality'.
John-cat is succeeded by Sheppard-cat, and then by Major and Colonel, and finally by You Idiot.
He grows so used to futility that when he returns from his visit to SGC and points beyond, he spends a whole day just staring blankly at his office wall, completely at loose ends. Eventually he picks up the phone and dials Jeannie's number. Just because his whole timeline is going to be reset doesn't mean he shouldn't try to mend a few bridges in the interim.
John is ... John is John, sarcastic and impatient and expecting the impossible. He's more vibrant--and less cooperative--than the John in Rodney's copied-over memories. It's the best thing Rodney's ever experienced, as either man or digital copy.
It also removes any deeply-buried, lingering doubts Rodney might have had about the wisdom of this whole little endeavor, aside from the terrifying stretch of time it takes for John to regain consciousness after his death-defying stroll through the desert. (Though the question about sports teams before he hops into the stasis chamber suggests that there's no lingering damage beyond that which had been sustained long before he'd arrived in Atlantis the first time.)
Rodney really ought to shut himself down, as he'd done for the first 48,000-year wait, but in comparison seven centuries seem like a blink of a (very slow) eye, and it feels wrong to even contemplate doing something besides keep watch over the stasis pod. Just in case.
The John who arrives back on their doorstep isn't quite the same as the one who'd gone missing. He's ... sandblasted, maybe. A little raw, definitely uncomfortable, almost vibrating with the need to get gone again, to make the rescue that apparently didn't happen the first time. Or didn't go right, or whatever. Rodney doesn't have all the details, and he doesn't really want them. While it's flattering to the ego to know that some version of him had been the one to orchestrate John's return, he doesn't like the distorted glimpse of his future that it gives.
(He's already resolved to contact Jeannie first chance he gets after the latest crisis is settled and Teyla's home again where she belongs.)
But he's still John, still determined not to leave any man--or woman behind, still sarcastic and impatient and expecting impossible things. And Rodney can feel himself stretching to match those expectations; as he always does, and always will.
Even forty-eight millennia in the future, apparently.
(So what if he's going to go bald? Forewarned is forearmed and all that. He'll just have to surreptitiously raise the question of Ancient healing tech's effectiveness on hereditary traits, next time he has a meeting with the expedition's medical team. Maybe Keller will have some ideas....)