I think this analysis as a bit guilty of over-fitting -- it is quite easy to rote memorize a bunch of things while having little to no understanding of what they are or how they work. Trivial examples include training a room of people to memorize a series of facts written in a language they don't speak (the fact that they have memorized doesn't at all mean they have any understanding of the content). So I would say it's not memorization per say, but meaningful exposure to a thing, the more chances you have to meaningfully interact with a thing, the higher the chance is you will learn how to manipulate it and do things with it. This is the difference between understanding and mere memorization, and the more exposure you have, the greater the chance you will start to see the patterns and understand, versus focusing your efforts on memorizing which will just lead to over-fitting and not understanding. As with NNs, so with humans.