If you are wanting to learn more Linux internals AND create something maintainable, you can create your own distro using Yocto/Bitbake. LFS teaches you all about Linux internals, but kind of leaves you to twist in the wind afterward. I would argue that Yocto exposes those internals AND gives you the ability to maintain the distro you’ve created (roll your own packages, pull in kernel patches/versions/modules, scan for applicable CVEs, etc.)
Or Gentoo sounds cool. Maybe an easier intermediate step before rolling your own.
“intelligence is a nuanced topic” Understatement champion. Applying your examples “in any form” still doesn’t really work since those examples are built on communicating the steps as well as the result. If an animal can intuit precision without showing the work, do we still give credit for intelligence? Jumping spiders, for example, have an extremely developed intuition for parabolic trajectories, but I’d bet real money there’s no neural structure in their brains that looks like y^2 = 4ax.