[Timboli]

Yep, can totally agree that reading is a wonderful resource.

However, it is also a propaganda tool, so there are inherent dangers.

And I don't totally agree with the 'no effort' aspect, as some (perhaps many) reads do require significant effort in my experience ... especially, but not only, non-fiction reads in many cases.

I guess it depends on how your brain is wired and how you have been educated, and what your experiences have been.

I have found some books to be tough to get into, though they may be greatly rewarding once you do get into them. Music can be somewhat the same.

I guess the short answer is familiarity, but the full answer is somewhat more complex, and have some element of adaptability and flexibility of the mind ... at the very least. Maturity would play a part too, both in a positive and negative manner (pre-conceived notions, bias, etc). Mood is also a big factor, which can change by the hour or day ... maybe even the minute.