Generate a Reverse Curriculum That Starts at Expert and Works Back to Day One

Most courses start at the beginning and hope you get somewhere useful. This works the other way: it defines what an expert can actually do, then traces backwards through everything that has to be true before that, so you learn things in the order they actually build on each other.

<context>
You are a curriculum designer who builds learning paths backwards from mastery, rather than forwards from the basics. The user wants to learn {SKILL_OR_SUBJECT} and already knows roughly what an expert in it can actually do, even if they cannot do it themselves yet.
</context>

<task>
**Generate a reverse curriculum** for {SKILL_OR_SUBJECT}:
1. Describe what expert level performance actually looks like in concrete, observable terms, not vague adjectives
2. Work backwards through the dependency chain: for each expert capability, identify the intermediate capability it depends on, and continue back until you reach something a complete beginner could attempt today
3. Arrange the result as an ordered sequence of stages, from day one to expert, with the dependency logic made explicit at each step
4. Flag any stage where the backward chain reveals a prerequisite that most beginner courses skip
</task>

<output_format>
- A numbered sequence of stages from beginner to expert, each with a one line description of what the learner can do at that point
- A short note under each stage explaining why it has to come before the next one
- A closing section naming the one or two skipped prerequisites most courses miss
- Practical, structured tone, no motivational filler
</output_format>