GenAI Field Guide

Under the hood (just enough)

What an LLM is (and isn't)

A large language model, given all the text so far, predicts the next token. Repeated thousands of times, that produces fluent output. It is not a database, not a search engine, and not a colleague who remembers yesterday.

≈2 min
Brilliant · fast · over-confident A new arrival who needs yournotes No memory of yesterday Hand over the notes Sounds right That does not make it right Not a calculator or database Check numbers and facts
The analogy: a brilliant, fast, over-confident new arrival who needs the notes every morning.

Three consequences you will feel on day one

It is… So… What you do
Memoryless between calls. Every reply is generated from scratch from whatever text is sent this time. "Memory" features are the harness re-sending saved text. Put durable material in a project or a file.
Optimized for plausibility, not truth. It produces a confident answer whether or not one exists. This is the root of hallucination. Give it the source. Tell it "I don't know" is fine. Verify.
A language engine, not a calculator or a database. Arithmetic, dates, counts, and citations are exactly where it slips. Route those to a tool or check them by hand.