Many of the Orbit prompts in this guide are of this kind. They're meant to keep you in contact with these ideas until you can make sense of them as you write your own prompts. Odd as it may seem, I often write such prompts about my own ideas in the course of my creative work. They help me muse on an inkling or question over weeks and months, until it can hopefully grow into something more. This is one way prompt-writing can create understanding which extends beyond simply capturing knowledge from a text.
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this almost seems like a way of keeping more open problems top of mind... open problems. I think that surfing your knowledge graph re-exposes you to open problems, but perhaps that is more haphazard and less reliable.