>> if I'm being 100% honest, I don't even recall the majority of them.
100% this. A lot of these concepts go over your head if you haven't seen a practical application for them. By the time you've encountered such a use in industry, the knowledge is long forgotten.
Yes, but the point of memorisation is you can much quicker re-learn the subject and you know there is a solution to a problem when you face it. If you have never learnt it, you don't know that there is a solution, or you start to optimise things in a way that is proven to be wrong. You might not able to recall them, but the knowledge is likely there in your subconscious.
100% this. A lot of these concepts go over your head if you haven't seen a practical application for them. By the time you've encountered such a use in industry, the knowledge is long forgotten.