1. John Sheppard's a better man than he is. Verging on suicidal at times, perhaps, and with a dark streak that's pretty well hidden, but he would offer himself up for vivisection if it were the only way to keep his people alive. (Sometimes Rodney thinks he has, in some way no one's quite noticed--but then John does something like spend a stolen hour racing remote-control cars, and Rodney decides he must be imagining things.) Rodney couldn't do that. Not even for his team. And thanks to Kolya, he can't even tell himself otherwise.
2. Anthropology can, on occasion, be useful. Anthropologists, on the other hand....
3. Jeannie was right to put family first, although he's still not entirely convinced about her choice of husband.
4. He's not really that allergic to citrus.
5. When he was younger, he would have scoffed at anyone who said this, but--he can't do this. Any of it. He's not good enough and doesn't have enough time or the right equipment or the needed information. He's not enough. They all should have been dead a long time ago.
(But he can't let himself think that or he'll be paralyzed and they'll all be dead for real, so he walls the knowledge away and every time they manage to survive despite him, because of him, the wall gets a little thicker and it's a little easier to pretend it's not there.)