Perspective1 July 2026 · ~7 min read

A few ideas power all of AI

Six core ideas, reused everywhere. Master the small core and each 'new' model becomes a variation on a song you know.

Try it live. The idea that reappears most: follow the slope downhill — how every model learns.

Set a learning rate, then Step downhill

Loss surface

Step 0

loss = 6.25

x = -2.5, gradient = -5 · One minimum at x = 0. Convex — descent always finds it.

AI can feel like an endless list of intimidating names — transformers, diffusion, PCA, SVMs, RAG, backpropagation. It looks like you'd need to learn a hundred separate things. You don't. The secret that strong learners know is this: the whole field runs on a handful of core ideas, reused everywhere. Learn the base once, and each "new" model becomes "oh — it's just those ideas again." That's the leverage a foundation gives you.

The core toolkit (it's shorter than you'd think)

Almost everything in modern AI is built from these:

  • Vectors — lists of numbers that represent things (words, images, data points).
  • The dot product — one number measuring how aligned two vectors are.
  • Softmax — turning scores into probabilities that add to 1.
  • The gradient / derivative — the slope that tells a model which way to improve.
  • Probability — reasoning under uncertainty; updating beliefs with evidence.
  • Matrices — tables that transform vectors into new vectors.

Six ideas. That's most of it. Now watch them show up everywhere.

The same ideas, again and again

Every post on this blog is secretly built from that short list:

  • Embeddings = vectors + the dot product (cosine similarity).
  • Attention (the engine of ChatGPT) = dot products + softmax + weighted sums.
  • A neuron = a dot product + a bias + a switch.
  • Training anything = following the gradient downhill.
  • Backpropagation = the chain rule (a derivative idea) run backward.
  • PCA = variance + directions (vectors) that capture the most spread.
  • Next-token prediction = scores → softmax → probabilities.
  • Bayes / spam filters = probability, updated with evidence.
  • SVMs = dot products + the widest-margin idea.
  • RAG = embeddings + cosine similarity + a language model.

Notice the pattern? The dot product alone shows up in embeddings, attention, neurons, and SVMs. Learn it deeply once and you've partly learned four "different" topics. That's not a coincidence — it's why foundations matter. The field isn't a hundred islands; it's a few deep wells feeding everything.

Why this changes how you should learn

If AI were a hundred unrelated tricks, cramming each one would make sense. But it isn't — so cramming is the worst strategy. The winning move is to go deep on the small core, because every hour spent truly understanding the dot product or the gradient pays off across a dozen future topics. Surface-learn the core and every new model feels like starting from zero; master the core and new models feel like variations on a song you already know.

This is also why "keep up with AI" isn't the treadmill it looks like. You're not memorising each week's new model. You're recognising the same few ideas, recombined. The person with strong foundations reads a brand-new paper and thinks "ah, attention plus a new trick" — while the person without them sees only noise.

The takeaway

You don't need to learn everything. You need to learn the right few things, deeply — the vectors, dot products, gradients, and probability that keep reappearing — and then watch the rest fall into place. A strong, small foundation isn't the slow path to understanding AI. It's the only fast one.

Here's the idea that reappears most. The demo below is gradient descent — the single "follow the slope downhill" move behind how every model learns. Understand this one, and you've understood the beating heart of the whole field.


Build the core once and everything gets easier. Try a free lesson or check where you stand.

Now build it — don't just read it

This is one idea from a full curriculum where you predict, build, and explain every concept — with an AI tutor that gives hints, not answers. The first five lessons are free.

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