> Mere exposure does not make you learn/enjoy a language.
It totally does. Especially when you're young. I think you thinking about a lower amount of exposure though. It needs to be quite a lot, not like hanging out at a French-speaking family once a week, but more like watching 30-45 minutes of subtitled cartoons/shows daily.
(maybe it was more, not sure how much TV I watched when I was little, and how much of it was subtitled. I do remember my parents didn't let me watch The A-Team because it was just about guns and violence ... :P :P)
Also, you can keep your position, but so far there are several people from all over Europe and elsewhere, confirming personal anecdotes about the difference subtitled TV shows make.
I want to emphasize the difference it makes whether you are young or not. The effortlessness by which young kids pick up languages, seemingly through osmosis, is just insane. I work with kids a lot, some of them come from crazy places, the younger they are, often after just a year in NL, hardly even an accent (translating for their parents at 8). On the other hand, adults that move here, even in their early twenties, if they don't make an explicit effort, forget it, after 3-5 years they still speak three Dutch sentences (I admit that it doesn't help that any Dutch person will immediately switch to English as soon as they hear you're having a tiny bit of trouble with the language. Not the case for small children, of course. Unless they already speak English).