# (Fantasy) -> (Planning): A Core Mental Move For Agentic Humans?

So there’s this thing where…

Back when I was young, I watched the movie Atlantis, and then spent a while thinking through how to build an actual city- or continent-sized underwater dome. What materials would be required? How much would it cost? How would light and heating/cooling work? Etc.

A similar example: I watched the Harry Potter movies, and then spent a while thinking about how to build a quidditch field with flying broomsticks kept aloft via magnetic levitation. Or a golden snitch capable of flying around my room; that one progressed to the point of fiddling with physical prototypes (which did not work, to be clear; I was a kid, I did not have any serious engineering knowledge yet, and I did not understand just how far beyond my knowledge-at-the-time such a project was).

Both of these examples show a similar mental move: (encounter a fantasy) -> (figure out how to bring that fantasy into reality). It’s fun, trying to work out the key steps and details to make the fantastic real. Even if it often fails.

To me, this move feels particularly foundational and load-bearing; it’s a core part of a healthy agentic human mind. It’s the mental move which goes from e.g. “Man, it would be cool if I could just make my own covid vaccine” to “Wait, what exactly is involved in making a vaccine, especially if one doesn’t need to pass clinical trials (because it’s for self use)? Are the biohackers already doing this? Let’s do some googling[…](https://www.lesswrong.com/posts/niQ3heWwF6SydhS7R/making-vaccine)”. Or Aella bored at an orgy going from thinking “Man, I wish someone would just come drag me off despite my apparent lack of enthusiasm” to “Wait, what kind of party structure would make that actually viable, what would the vibe and rules be, which friends can I rope into organizing this, […](https://aella.substack.com/p/how-my-consensual-nonconsent-orgies)”. Or any number of entrepreneurs going from “Man, I wish I could just <blah>” to “Wait, what would actually be required to allow people to just <blah>? What’s needed technically? How could one deliver it to customers? What kind of pricing would be necessary, and how much would people be willing to pay? …”.

Notably, I don’t think most peoples’ thinking most of the time routes through the (fantasy) -> (planning) move. Instead, we tend to be less backchainy and more forwardchainy: noticing when options are available, and then deciding based on whether an option feels locally-good or locally-bad. There’s no particular fantasy or vision driving that kind of thinking.

Looking back, the (fantasy) -> (planning) move has been a core driver for me to learn a lot. I considered questions like “How would one build a continent-sized underwater dome?”, and questions like that left me strongly feeling the need for a structural engineering course. I considered questions like “How would one make a quidditch stadium with real flying broomsticks?”, and questions like that left me strongly feeling the need for a course in electrodynamics (... which includes magnetic dynamics, but the course is usually called “electrodynamics” or something like that). I considered questions like “How would I make a real living dragon?” or “How would I make a robot to do my chores?” or “How would I make a water fountain which can maintain a 3D human shape made of water?”, and such questions left me feeling the need to study developmental morphology or underactuated control or computational geometry. As a general rule, if I felt the need for the same subject from a few different independent questions, then I studied the subject.