What Americans blather on about when they are talking about their free speech isn't anything resembling free speech. They're not arguing that they shouldn't be unfairly punished by the government for holding or stating a particular belief, ideal, value, creed, philosophy, or allegiance.
They're arguing they should be able to say whatever the hell they want and you just have to listen to it without exception, and that they should not receive any negative response or argument against it. That's not freedom of speech they're asking for, it's freedom from consequences. They want to be able to say anything they like without concerning themselves with inconveniences like accountability or responsibility.
It's true that not all Americans lack an understanding of the concept of free speech. It's not my intention to suggest that the nation as a whole misunderstands it. However, the ones that do understand it tend not to be the ones vocally shooting their gobs off about it. I find the ones that frequently bring up their free speech are the ones doing it in circumstances that have nothing to do with it. Those that do understand free speech generally keep their mouths shut about it because they know it has nothing to do with it most of the time.