Not memorize–be literate. One of my favorite pieces, culturally speaking, from the Torah is a section from Judges, where the judge is betrayed by a town’s leadership; surviving the betrayal, he has a shepherd boy from the town write down the names of the betrayers, and it is not taken as anything other than expected that the boy is literate. I think that one of the reasons for the longevity of the Jewish culture is that expectation of literacy and cultural transmission.
As was pointed out to me by an Orthodox friend of mine recently, the majority of European religions two thousand years ago were some form of mystery cults, where only the initiated inner circles were knowledgeable about how the rites were performed, and now we know very little beyond educated guesses and second-hand sources of how, say, the cult of Dionysus, or the cult of Isis, or the cult of Odin actually did the specific details of their worship. But for Judaism? The holiest of the holy rites? The ones that, if the high priest does them incorrectly, will result in his death? All written down for reference, in detail, for everyone in the culture to be familiar with.
