Comment by adrianN

Learning a language at any age is hard. It's just harder to fit in thousands of hours of deliberate practice in your thirties than in your teens. As the author correctly notes one needs to know tens of thousands of words to have a reasonable chance of getting through a text without encountering an unknown word. To get to that number a spaced repetition system is much more useful than sticky notes, but it doesn't help much with the time needed for practice.