I should probably warn that this is a mix of canon/personal canon, which means John's family history is different, but everything else should be the same. I think. It's been a while and I didn't look anything up.
The bed was too short, and no matter how John folded his legs or bent his back, the bed remained too short and he remained awake. But given the event he knew his dreams would replay,awake was fine by him.
He’d shot his commanding officer. Shot and killed. And yes, it had been Sumner’s last (silent) order to him, but still.
Atlantis hummed quietly at the back of his thoughts, and he wanted to be grateful for that, wanted to be awed and excited and a little in love with her, but he couldn’t keep from circling back to the thought that maybe it would have been better to stay at home.
(Except there wasn’t any home for him to have stayed at, was there?)
And just like that, they were back on Earth and buried beneath a mountain, as though there had never been a city that sailed the sea. Or them in it. John in it.
He bought a white noise machine, but it didn’t help him sleep at nights.
(He didn’t dare try the ‘ocean waves’ setting; it wouldn’t be right either, but it would be less wrong, and he daren’t cry for fear of never stopping.)
At some point, in the middle of some mission gone very wrong, he found himself thinking about where he’d be if he’d stayed on Earth. At the farm that would always be his grandparents’, most likely, out in the fields with his second cousin, or on the sofa watching football, legs covered in dog hair and love. He’d know how Bill liked his eggs in the morning, and where he spent his Sunday mornings. Whether he ever dreamed of having a family, as John once had, long ago.
(As John had once had, before life happened.)
It wasn’t allowing Elizabeth to die that nearly broke him, but rather Rodney resurrecting (a semblance of) her; monkey’s paws were only fictional on Earth. On Atlantis, they were pretty but all too real.
Someday, John knows, he will look at the stains on his soul, the ones placed there by (Atlantis) Pegasus, and they will be too dark, too deep to ever remove. And on that day, he will wish that the coin toss had gone the other way and he had stayed on Earth, where his scars were clean and self-inflicted.
But he will only wish it once before smothering the thought forever. It is dangerous to make selfish wishes that are true while living a city that can hear them, in a galaxy that is as cruel and inventive as it is beautiful.
And then he will be a different man than he now is.