I was in high school when I first read this opinion (I did not remember it was Socrates though). Also, I learned that Gaul, pre-roman France (where I lived), had a society where the priests/judges, the druids, were forbidden to write down their knowledge.
It fascinated me. The idea that books, that were more or less revered depositories of knowledge, could have been seen as anti-intellectual at one time. It pushed me into memorizing stuff. I think it had an unanticipated effect. I thought it would help my overall cognitive capabilities and make me maybe better at science and maths but instead, it gave me a taste for poetry.
If you learn poetry for the sake of it, not because you have a recitation exercise, after a while, it become easy. It is not like memorizing the digits of pi: good poetry has a flow. A flow of sounds, a flow of words, a flow of meanings and a flow of emotions. It is easy to dismiss them when you simply read it, but having to learn it makes you connect deeply to the meaning. Hearing it also has a different effect. I now understand why poems, that I used to find uninteresting when skimming over them in books were actually so highly regarded back in the time.
That was an interesting experience, but Socrates missed a trend that continues nowadays: the volume of accessible information grows. We need faster processing modes. We need written text so we can skim through a page and dismiss it in a few minutes. We can't do that with oral transmission.
That must not make us forget that deeper modes of thought exist. Once we have googled the words we did not know, wikipediaed the summary of the knowledge we lacked, we must fight the urge to keep the flow of information going, reach out to the off button, and dare to stay an hour or two with our mind. Thinking.
We memorize things by exerting recalls. We understand things by banging our heads over what we don't understand about them. Acquiring the knowledge is just the first step of acquiring understanding.
In this day and age meditation becomes popular amongst intellectuals for a reason, but even if you are not into meditation, do yourself a favor when you learn new things: think about them with only your brain for an hour or two. Thinking does take time but without it information gathering is useless.