Ask HN: Did I hit the Programming Wall?

I am currently teaching myself programming in Python 2. I attempted to learn programming in Java before, however, I ALWAYS hit the brick wall at OOP. I understand the abstract concepts, however, calling classes and functions (like calling a variable in Python 2 from a class in a imported file, etc.). I just had never understood OOP. I understand literally everything else, like functions, variables, debugging, etc. Any advice for me?

Thanks!