"And the final level? Believe it or not, being able to follow a conversation between a large group of native speakers is the last piece of the puzzle to fall into place. Or at least it was for me. Once that happens, and you’re able to interject, come in and out of the conversation at will, you’re pretty set. After that, there’s not really anywhere else to go without living in the country for at least a year or two and reaching complete fluency."
What does the author really mean by the last sentence?
Does it mean, "The last phase is that you need to live in the target country for one or two years and then you will become completely fluent in the target language"?
Thanks a lot for your kind help.