Sometimes—not very often—Rodney misses Earth things. Like unlimited supplies of coffee and chocolate. The certainty of time-tested laws of physics. Cats.
Coffee and chocolate arrive in regular shipments on the Daedalus, which is better than the tiny supply they'd brought with them in the first place, before they'd reestablished contact with Earth. He can't run out to a convenience store for a caffeine and sugar fix at two in the morning, but mostly it works out tolerably well.
He can't do anything about the laws of physics in Pegasus except make his own observations, like Newton and Einstein. Which is, of course, incredibly exciting—when his life and the lives of his teammates don't depend on it. And his observations will undoubtedly contribute to winning his Nobel.
There are no cats in Pegasus. There was that small feline-esque creature that had followed him home on M2X-991, but he hadn't been able to convince Sam to let him keep it. (Wild animal, distraction, too many emergency situations when it would only get in the way, blah blah blah. He kind of regretted naming a whale after her.) He doesn't even have a cat back on Earth anymore, having told the girl next door that she could keep Doppler for good the last time he'd been back. There just wasn't much point to having a cat you couldn't cuddle and, besides, Earth isn't home anymore.
But he does have this:
A lazy summer afternoon, between crises, with the windows open and sunlight spilling across the bed. John sprawled out with his head on Rodney's belly. The sound in the back of John's throat that's almost like purring when Rodney absently runs a hand through John's hair while reading idiotic lab reports. The vague grumbles of protest when he gives up on doing work and shoves John's head off his stomach so he can lie in the pool of sunlight, too. The way John drapes an arm and a leg over Rodney once he's settled, so that he's half on top of Rodney. The hour they spend drowsing like that, with John's breath warm against Rodney's throat and the occasional brush of his lips against Rodney's skin.
Sometimes—not very often—John misses Earth things. Like watching live football games. Flying planes and helicopters. Ferris wheels.
They get copies of old sports games as part of the "recreation packages" that are sent periodically on the Daedalus and the Hail Mary video he brought with him never gets old (especially because Rodney's vociferous complaints at watching it again are always amusing). And trying to teach Ronon and Teyla to play with the Marines when a real football had turned up in one of the shipments was fun. Ronon had caught on quickly, but Teyla remained baffled by the point of it. "The point is the adrenaline, the team, the strategy," he'd tried to explain once. But Teyla had just continued to stare at him blankly and opted to watch from the relative safety of the sidelines with Rodney.
He has a bay full of puddlejumpers at his command and he's even flown the city, but it's an entirely different experience from planes and helicopters. Flying something that responds to your every whim (with the lamentable exception of providing turkey sandwiches on demand) never stops being cool, but sometimes he misses the challenge of flying when your success depends solely on the mathematics of your velocity and altitude.
They've yet to encounter a civilization with an amusement park. But then, every advanced civilization they've met has developed their technology for one purpose: to survive. There's not enough time for amusement in Pegasus. He doesn't let himself think about the future much—there're too many uncertainties—but sometimes, just for a few moments, he imagines the Lanteans building an amusement park for the galaxy, near a Stargate so anyone can come, and he and Rodney will ride on a Ferris wheel far above exhaustion and fear.
But, for now, he has this:
A warm summer night on his balcony with Rodney after a run-from-the-natives kind of mission, the silvery light of two moons casting strange shadows around them. The way their noses bump together as they examine each other's scratches and bruises with chapped lips. The slow sighs of their breathing creating a counterpoint rhythm to the sound of the ocean rolling gentle waves against the edges of the city. The warm taste of Rodney's tongue when they finish going over the day's catalog of injuries and finally bring their mouths together. The rush of exhilaration John feels in his chest and belly every time Rodney kisses him, like the rush of going down on a Ferris wheel—an exultant centripetal force that ties him to this moment while the rest of the world spins on somewhere far beyond the arc of Rodney's lips.