Normally I wouldn't bite on a personal slander like yours but in this case I think it may be valuable to undermine your poor stereotypes.
By the time I was 21 I had lived in 4 countries on three continents and outside of the US for 1/3 of my life. I was fluent in Russian, conversational in Turkish, and studied to a functional tourist level in Spanish and Arabic. My little brothers are fluent in Estonian and Bulgarian. Additionally, although equally anecdotal, I know at least six Americans that live within a suburban block of me who were fluent in a second language including Japanese and Korean. I have coworkers who were fluent in Spanish, Dutch, Tagalog, Portuguese, and Esperanto.
I say "were" because language fades with time.
I don't mean that they studied it in school. All of these lived in the respective countries for some period. (Except the Esperanto, of course, but he also speaks Spanish).
I'm not saying this to try and impress. Many people have learned more and at a younger age (especially when they live in small countries).
You are correct that there are many Americans who are internationally ignorant, like in all large, insulated countries.
You would be foolish to assume that we all are.