Someone on another thread mentioned something about a teacher who told them to read a certain number of books in English in order to be fluent, but I can't find the thread and don't remember the number

Has anyone ever heard of a number for something like this?
I find that in French, I am a better speaker than I am a reader (because when I speak, I can just use words I know) and I want to cross that intermediate barrier into full fluency. I am good with general vocab---on a typical page, I might look up two or three words for actual translation, and I can often get through several pages without looking up anything. But I still panic a little at all the fancy verb tenses. I recognize that something is a form of a certain verb which I know, and even might recognize that it is a past tense form, but I get hung up on what exactly the actual translation to English is (I went, I would have gone, I did go etc.) and so get slowed down.
I am assuming that with enough experience, I'll get better at this and might eventually become truly bilingual. On average, how long does that typically take? It's not that I am waiting to complete a certain number of books for any kind of validation or prize, it's more that I want to know how much time I am going to have to budget for this. 1,000 books? 5,000? More?