Gigi
Everything. I mean, we were designed, recombinant DNA hybrids, human/avian. And the School with their tests and the Erasers and even Jeb when we got away, but then they got Angel again and the rest of us, well, no, Max and Fang and Nudge went to go get her, they left me and Gazzer behind, because I'm blind and Angel's his sister, but then there were more Erasers and we had to go. Caught up with them later, and got Angel back, and then found out that getting away in the first place was all part of the experiment, and so we left it all behind and then we found my parents, and I thought they were going to be freaked out, but they were fine, mostly because I could make the millionaires, so I went back to find the Flock again, since they're my real family, and then I ended up here instead.
...Sorry if that doesn't make a lot of sense, I haven't really thought about it since I got here, and haven't tried explaining it to anyone except Navi, and it makes her cry, so I don't.