The advice to "start with a story" is usually given as a rhetorical trick. It is actually a cognitive one.

What the story does

An abstraction with nothing to attach to slides off. If I open with the afternoon I spent chasing a route that kept reverting to the home page, everyone in the room now has a concrete instance in mind, and the ten minutes about hydration mismatches land on something. Without it I am describing a category to people who have no member of it.

Rules I try to follow

• The story must be the actual subject, not a warm-up. An anecdote about airport security followed by a talk on caching wastes everyone’s first two minutes.
• Include the part where I was wrong. It is the most useful content and the part audiences remember, because it is the only part they cannot get from documentation.
• Keep it under ninety seconds. It is a doorway, not a room.
• Return to it at the end. A talk that closes by resolving its opening feels finished in a way a summary slide never does.

The hakawati knew this too: you do not begin with the principle. You begin with a man, a night, and a problem, and the principle arrives on its own.