I know what you mean. For myself, I have learned quite a bit about Japanese culture by watching anime and reading books. The only problem with learning through media this way is that one needs to be careful to stereotype the culture because of the media seen. It is somewhat similar to looking through a microscope and seeing a sample and assuming that all other samples look that way immediately after.
As for the amount of information needed to blend into a culture, you are absolutely correct, which is why I have found that tuning into one part of any given culture (usually its pop side) let's me learn quicker.
Study Japanese with Suzumiya Haruhi
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