4 ideas
Ireneo Funes, a young man from Fray Bentos, Uruguay, is thrown by a half-tamed horse and left crippled, and from then on he perceives and retains every detail of every moment. He can reconstruct a whole day, though doing so takes another whole day, and he teaches himself Latin from a borrowed dictionary and Pliny. He lies in a darkened room, cannot easily sleep, and dies of pulmonary congestion at twenty-one.
To think is to forget differences, to generalise, to abstract. Funes cannot see that 'dog' covers both the dog at 3:14 seen in profile and the same dog at 3:15 seen from the front, because every instance stays vivid and distinct. Forgetting is not a flaw in thought but the operation that makes thought possible.
He also plans a language in which every individual stone, bird and branch has its own name. Such a scheme preserves every particular but destroys the thing that makes a system useful: compressing many cases under reusable rules.
Read Funes's memory as a lossless recording, and the lens shows that fidelity and insight trade off. A perfectly detailed record of the world is as unwieldy as the world itself, much as a map at 1:1 scale is useless. Understanding comes from deliberately discarding information, so any system that keeps everything without a way to prioritise or summarise stalls in particulars.