It does bring faster results than traditional learning, but if you stop working on your input and fluency, you will lose it.
If you do not use it you lose it.
Just like training your muscles. After disciplined and constant training over a few months you feel happy with your body, but if you stop training you’ll go back to where you were.
The same goes for your fluency in the second language.
If you stop practicing, stop working on your language input, stop listening to your alpha-theta sentences, you’ll get ‘flabby’ or your language ‘muscle’ will get ‘flabby’. It will lose its firmness.
What do language learning, building your muscles, playing the musical instrument or working on your spiritual and personal growth have in common?
They all require constant, steady, long-term approach forever.