One of the core components in a good system of memory is having the ability to imagine things vibrantly. It doesn’t exactly have to be visual — but the more senses one can involve, the more reaction one might have to a thing, the better.
This is involved in both the Linking Method, where something is imagined strongly and then linked to other things and the Method of Loci, where something is imagined strongly and then placed in an imaginary route.
Putting aside that these techniques are only good for objects, and you’d need something like The PAO system for other kinds of things, it’s clear that in order to make use of these memory systems(And perhaps to have a good memory in general), you’re required to strengthen and enhance your own imagination. Everybody can imagine (Even those who aren’t capable of visualizing)