I'm fluent in four, but the vast majority of people in the US appear to speak only one. The case is similar in Germany, France and Spain, at least from my experience. As such, bilingualism is not a pinnacle of achievement (is anything ever a pinnacle of achievement) but rather a recognition that ANY other language has value of this kind. Once you get past "I can do just fine with one." you can go as far as you like. But the step from one to two seems to be the critical one.