What sophisticated idea are you holding on to that you are sure has been formalized somewhere but haven't been able to find?

The influence of the British Empire on progressivism.

There was that book that talked about how North Korea got its methods from the Japanese occupation, and as soon as I saw that, I thought, "well, didn't something similar happen here?" A while after that, I started reading Imagined Communities, got to the part where Anderson talks about Macaulay, looked him up, and went, "aha, I knew it!" But as far as I know, no one's looked at it.

Also, I think I stole "culture is an engineering problem" from a Front Porch Republic article, but I haven't been able to find the article, or anyone else writing rigorously about anything closer in ideaspace to that than dynamic geography, except the few people who approach something similar from an HBD or environmental determinism angle.