neumanc wrote:(3) How structured should your learning be? If you just watch TV, you happen to learn the language used in your favorite TV series. If you like detective series, for example, your vocabulary would be quite skewed. Would you be able to discuss political systems or climate change? Would you even be able to understand basic cooking recipes or name all the different kinds of animals even small children are supposed to know, at least according to children's books?
I personally don't care about learning things that children should know. I largely focus on learning things that I want to say or understand when I come across them. I've put in 900 hours with Polish and I still don't know the days of the week or the names of most months because I don't at this point have a need to know them. I'll get to them at some point, but there are other things I'd rather learn first.
With Italian, I started out by asking my husband (native Italian speaker) how to say some simple sentences that I actually wanted to say. Things like, "I'd like a glass of wine" / "I'm not hungry" / "Can I have the salt". Sentences like these were usable immediately and I found them much more useful to interact with my non-English speaking in-laws at the dinner table instead of memorizing a list of colors or animals or other "basic" vocabulary.
In choosing native material to watch/listen/read, I decide based on what I'm interested in and what skill I want to improve. I watched extensively and intensively TV series on Netflix to focus on sentence structure and general colloquialisms/phrases. I chose one series (That 70s Show) because it was about a group of teenagers doing everyday things, and were likely to use a lot of language that I, myself, wanted to be able to use.
The benefit of using native media is that you will learn current and useful speech patterns, as opposed to artificial dialogues in textbooks that don't accurately capture how people talk. I remember a few years ago my husband saying that he was really pissed off that he spent so many years studying English textbooks in school that all had dialogues with people saying things like, "How are you doing?" because then he was woefully unprepared to deal with native speakers who rarely if ever spoke like that.
If the only thing you ever watched were skateboarding videos, then you probably wouldn't understand cooking shows very well. Which is a great reason to vary what you watch and listen and read to, and try to expose yourself to a variety of native materials. If you mainly just read history books because you love them, then your vocabulary will probably be skewed (but then so would a native speaker who only ever read one specific thing to the exclusion of all else), but it will also be incredibly rich on that specific topic and you will probably be able to discuss really well a topic that you are passionate about, so I guess it depends what the person's reasons are for learning the language. If it's for pleasure, then being able to discuss a topic that you're passionate about doesn't seem like a bad thing.
My dad is a native English speaker, but he couldn't hold much of a conversation about knitting or swimming; not because he doesn't know the vocabulary (he actually probably doesn't know any knitting or swimming terms now that I think about it), but mainly because he doesn't care about those topics. So I don't think language learners should stress about talking about topics they don't care about (unless it's a requirement for some reason or they just really want to be able to do it.)
So this fictional person who only reads history books may not be able to discuss climate change, but does he even want to? If he did, then I'd assume he'd want to spend some serious time reading and listening about climate change.