If you came from a mid-university and got accepted into a high ranking uni for postgrad, what was a concept you never learned yet was something you should have known about.

(I hope this is relevant for the subreddit)

For some reason in undergrad none of my modules (as far as I can remember) touched on the intertemporal budget constraint. I felt like a clown looking up videos aimed at undergrads to understand it. It was very much relevant in my optional modules as well.

I remember some people in my cohort didn't know about the different types of markets, didn't know how to feel about it since it was something I took in high school econ.