How do I approach learning data structures and algorithms?

(Part 1) First things first, as said in the title, how do I effectively learn data structures and algorithms? I've been thought in college about many useful algorithms and data structures, but if you asked me to write down that algorithm for you to solve a problem without googling it, then I assure you that I'll fail on your request. I thought memorization was an easy fix for such matter, and it initially worked for simple things like conditiona