When you look at a list of what the typical expat ought to be, introverted characteristics aren't usually on it. People expect expats to be extroverts and stereotypically extroverted character traits can serve expats well. You're thrown in the middle of completely new situations, new people, and new languages all the time.
It's especially hard for me, because I'm an introvert who also doesn't deal well with new situations. I'm not someone who loves change, although I am getting better at dealing with it. Being an expat requires a lot of action, especially at the beginning, and that's when I need time to figure things out. It's also hard for me when I'm trying to learn a new language because you're never going to learn to speak a language if you don't get out and try it. You might be able to read it, but speaking requires overcoming some introverted tendencies. Some days all I want to do is curl up in the house and not speak to anyone in any language and read familiar books that remind me of living where I'm a little more comfortable.
But being an introverted expat isn't all bad. You ought to expect some isolation as an expat (especially in a situation like ours) and that doesn't bother me at all. I don't depend on others to help me be content. There are also a lot of interesting things I can learn on my own- it doesn't all have to be about being with other people. And despite my distaste for new situation, I love new cultures, new languages, and new food. I can't experience all the things I want to in the US. Curious introverts can make great expats.
And I'm lucky to have a husband who has all the "right" expat traits. I'll supply the overlooked ones.