Explain a hard concept at three depths

Same idea, three levels — pick the one that lands.

Explain [CONCEPT] three times:

1. **In one paragraph** for someone who has never heard of it. Use one concrete analogy and say where the analogy breaks.
2. **In detail** for someone with [BACKGROUND], including the mechanism and why it works.
3. **The part people get wrong** — the most common misconception, and what's actually true.

No preamble. Start with the first explanation.