[rznicolet]

Small counterpoint to your analogy, as someone who studied astrophysics: I actually did have a requirement to understand general relativity! Deriving all of it independently from scratch wasn't something we did, but there _were_ derivations involved. And it was definitely worth working through -- it _is_ a good tool for understanding. (I've long since left the field, but I don't regret the work I did.)

[spongebobstoes]

that's exactly what I'm saying. understanding is good

you didn't re-invent it, you learned it from a teacher and then practiced until you understood it to the required degree

[Jtarii]

What you cannot build you do not understand.

If you can't derive a result in mathematics or physics from first principles you fundamentally do not understand it.