What's the point of listening to 3 books per day? You need time to digest the ideas in a book. Sometimes I listen to one chapter in a book and I need a whole day to digest it: I get into a state where I don't want to listen to _any_ music, etc.
Agreed, but sometimes there's value in having broad exposure ASAP.
e.g. learning what tools/techniques are available in a given discipline
e.g. learning enough jargon to Google for deeper exposure
This can be helpful in cross-disciplinary contexts. Perhaps you don't need to truly understand Statistics, for instance, but you're working on a problem in which you've binned a matrix of values into deck-of-card-like suits and you want to evaluate how "good" each choice was within its local context. It would help to know terms like "categorical variables" and "goodness of fit".