Having tried this in undergrad, lets say you’ve gotten through an Econ 101 text all the way through harder Finance math like understanding Black Scholes- you’re about half way. Now you have to learn about huge arbitrary or historical institutional complexity around how finance really works. The only way I can see how anyone keeps it in their head is they are paid to do it every day. Also there is not necessarily one truth to grasp, its more like studying climate change.