Why this book exists
There are two kinds of AI books. One wants you to be excited. The other requires a mathematics degree. This is a third thing.
Actually Understanding AI is a plain-language explanation of how generative AI actually works — the real mechanism, not the marketing version. It was written out of a deep allergy to explanations that sound impressive but explain nothing. It will not make you a researcher. It will make you dangerous to bad AI thinking.
What you'll walk away with
The real mental model
What a language model actually is, how it learns, and why it "hallucinates" — explained from first principles, not analogies that fall apart.
The 200 lines
Read a complete, working language model top to bottom. Neurons, attention, training — every piece decoded in plain language.
Practical judgment
Right tool for the right job: prompting, context, RAG, fine-tuning, and agents — so you can decode vendor claims yourself.
Inside the book
Six parts, twenty-five chapters, an epilogue, the complete 200-line code listing, and a full glossary — structured to take you from zero to genuinely understanding how these systems work.
Learn free at learn.tgifriday.com
The book has a free online companion: learn.tgifriday.com — an AI-literacy curriculum built on the same material. Seven self-paced tracks, from a 15-minute plain-English overview to a line-by-line walk through the full 200-line transformer. No account required.
Get your copy
Available now in the 2026 edition.
Buy the Book