From personal experience it's not an unusual arc. I've experienced it myself and heard from others, and it goes like this: you first move abroad and let's say you're happy, you enjoy some things that are new to you. But after a while, a couple of years pass, and you start getting the urge to go back, and it gets greater and greater. Disillusioned is too harsh of a word, again personally I don't think anything is essentially wrong in the country I live in now, but maybe you just realize it's not really yours. There's no place like home.
The one exception here is that this person was unhappy at the first stop in San Francisco, but otherwise in other places yes.