My family moved here when I was a kid, my mother tongue is another romance language and my mother used to teach French so it was a fairly simple process for me. If anything, English was a slightly greater challenge due to its almost complete absence at home (my parents would only watch TV in French), but that was easily remedied by the ubiquity of American and even English Canadian culture. I also happen to be fascinated with words, which attenuates the drudgery of learning.

Most importantly, the experience of exile has taught me that culture is a mask you must don in order to survive, especially when you come from a less privileged country. When you're not actually 'threatened' by the prospect of not blending into the host culture, you'll more easily cling to your pride and identity of birth, which you may return to later without incurring irrecoverable losses. But when you know there's no turning back, you further bury what's left of your roots and learn to become another—many others, even. It simplifies the process of learning a fourth and fifth language, and so forth, because you've had to make peace with the fact that there is no first language (exile overwrote it) and thus all words are equally shifty and equally malleable, a new skin you can slip into should the need arise. Thus, when learning a new language, my end goal isn't to pick up words but rather to become French, English, German, Spanish, etc. Insofar as I feel like my 'original' identity is lost forever (better yet: there never was one), the vacuum it left behind is now a placeholder for other identities and other tongues.

(I'm exaggerating for effect, but you get the drift.)