An Exocortex is a theoretical augmentation to a person's brain. It's basically extra functions and memory you could add to a brain to make people smarter.
They don't really exist yet, so this notebook is my exocortex in the meantime. I keep it full of notes for reference and sharing. Most are related to web development but could honestly be about anything - nonfiction, fiction, general life skills and topics, and whatever else I want remember without relying on my unreliable brain.