You can learn and practice a concept in two ways:
Option 1: You can learn the entire theory on a particular subject and then look for ways to apply those concepts. So, you read up how an entire algorithm works, the maths behind it, its assumptions, limitations and then you apply it. Robust but time taking approach.
Option 2: Start with simple basics and develop an intuition on the subject. Next, pick a problem and start solving it. Learn the concepts while you are solving the problem. Keep tweaking and improving your understanding. So, you read up how to apply an algorithm – go out and apply it. Once you know how to apply it, try it around with different parameters, values, limits and develop an understanding of the algorithm.
I prefer Option 2 and take that approach to learning any new topic. I might not be able to tell you the entire math behind an algorithm, but I can tell you the intuition. I can tell you the best scenarios to apply an algorithm based on my experiments and understanding.
In my interactions with people, I find that people don’t take time to develop this intuition and hence they struggle to apply things in the right manner.