[goldfeld]

I'd also recommend The Art of Memory, which is not only an introduction to the classic discipline of method of loci (memory theatres) and a great book dealing with history and art of the Renaissance, it even goes over the text of Ad Herenium, the greek classic that brought us this lost art. It's especially interesting for applications like storytelling (know all stories from your own life with perfect recall) and rhetoric.

Also deeply related to memory and cognition, this time coming from the older yet culture of the Vedas, there are celastrus seeds, aka the intellect tree, perhaps the oldest nootropic of all, and more natural and noticeable than most.