There is a chart on the wall of every chemistry classroom in the world, and its presence there is a decision about memory.
It lists more than a hundred elements with their symbols and their masses. Nobody is expected to learn those masses. They are on the wall precisely so that they need not be in anyone's head, and a student who spends a month memorising them has spent a month on the one part of the subject that is permanently available.
What a chemist does carry is smaller and far more useful: the behaviour of the eighteen columns. Everything in the first column reacts violently with water. Everything in the last is almost inert. Elements in the same column behave alike because of how their outer electrons are arranged, and that single idea explains more chemistry than any list of numbers.
The chart was designed to be looked at, not learnt.
Any subject with a reference table makes the same offer, and the same trap comes with it. The thing worth knowing by heart is never the part printed on the wall. It is the part that tells you which line of the wall to read.