The Great Mental Models of Modern LLMs 16 lectures

A lecture series  ·  Revised July 2026

The Great Mental Models of Modern LLMs

A 2026 technical report reads like a foreign language until one part of it becomes fluent. This series starts with that one part — attention, a single machine with a single argument — and only once it is second nature does it widen: how the experts are chosen, what precision the weights are kept in, how training survives trillion-token runs without exploding, and what happens to a model after pretraining ends.

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Start with attention, because it is one idea told four ways. Everything after it is the same kind of story — a cost, and the mental models invented to pay it down.
Part One (Volumes I–VI) is the argument over how a model remembers. By 2026 every lab agreed on the mixture-of-experts skeleton and then disagreed, in public, about attention — DeepSeek and GLM bet on trainable sparsity, Kimi and Qwen on linear hybrids, MiniMax tried linear, retreated to full, then shipped sparse. Parts Two through Four take the same instinct to how the experts are picked, what precision the weights are stored at, and how a model is trained and then re-trained after the fact. Fourteen lectures on attention; ten on everything the report says next.
I

The compute bill

Comparing every token to every token costs n². At 100,000 tokens that grid has ten billion cells.

II

The memory bill

Generation must remember every past key and value. Past a certain context the cache, not the weights, owns your GPU.

III

The silicon bill

Attention is starved for memory bandwidth, not arithmetic. The maths can be perfect and the kernel still slow.

Four answers, nine years

A genealogy · vermilion marks the mechanisms still being argued about

SHRINK THEMEMORY SKIP THEWORK CHANGE THEMATHEMATICS RESPECT THESILICON Multi-head attention 2017 · the original machine MQA2019 GQA2023 MLA2024 Sparse Tf.2019 Longformer2020 Window2023 Sinks2023 NSA · MoBA2025 DSA · MSA2025–26 Linear attn.2020 Mamba2023 DeltaNet2024 Gated Delta2024 KDA2025 FlashAttn2022 PagedAttn2023 Flash-32024 FlexAttn2024

Scroll the diagram sideways →

I
Part One · Lectures 1–14

How a Model Remembers

II
Part Two · Lectures 15–16

Choosing Which Parameters Run

III
Part Three · Lectures 17–18

What a Weight Is Made Of

IV
Part Four · Lectures 19–22

Training It, Then Teaching It Again

Coda · Lectures 23–24

Reading the Reports

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Reference

Appendix