" At any rate, it was clear that our backup crew would not fly Gemini 10. So when I heard from John Young (he and Gus Grissom had just come off the Gemini 6 backup crew) that he and I were to fly 10, I was overjoyed. I would miss Ed, but I liked John. And besides, I would have flown by myself or with a kangaroo, I just wanted to fly. All that stuff about crew psychological compatibility is crap. Almost anyone can put up with almost anyone else for a clearly defined period of time in pursuit of a mutual objective important to each. "

― Michael Collins , Carrying the Fire: An Astronaut's Journey