[jamager]

This is a valuable argument (learn in context, vary the context), but the mention of "people learn their MT without Anki / grammar / study" always bugs me.

First and Second Language Acquisition is just apples to bacon. The baby and adult brains are different, and their needs, capabilities, and context are vastly different.

[tianshuo]

Of course, babies and adults are different but more important is how language is learned or acquired. Most adults do not have mentally stimulating content that is basic enough. There is a dilemma where the content they need is the content they don't want to watch.