This. After finishing a BS in Maths, and with coding experience, I started a degree in Computer Sciences, thinking that I would know the most of it because I was coding since I was 15.

The truth is nope. You see a lot of things besides coding, with seems to be more important than to do a a while, compile a program or use a library. You learn the WHY, which most of the time is more important than the HOW.