Planet of the Apes

You're immune to the simian flu that nearly wiped out the human race a decade ago. And it turns out you're the only human in the ape colony. You blend in almost perfectly, you know sign language, and you live like one of them. The only ones who don't like you are those who were mistreated by humans, though even some have grown fond of you. After all, you were raised as one of them; you pose no threat. You live happily in the ape colony; they occupy the top spot in the hierarchy, above humans.