How Do I Become One of Those Writers Who Remember Everything?

The answer is yes, there is training. There is training for almost everything! I think we often assume that other people's learned skills must be innate talents. I know a lot about perfume and a fair amount about wine, so people are always saying to me, Your sense of smell/taste must be really good. And they are, kind of, but I wasn't born with some kind of sensory superpower; I was interested in smells and tastes, so I started paying attention, then looked for corroboration of what I noticed. By smelling a lot, and reading about smells, you can learn to have a good nose, and I think you can learn to have a better memory.