The most basic things are hard to grasp also. I had a really hard time understanding what is the difference between unicode, str, bytes and how to encode what when I started with it 5 years ago: https://stackoverflow.com/questions/14839028/how-are-these-s...

Nowadays, teachers have to start with generators and yield even for beginners, because most of the things are generators in Python3, which is not a trivial concept to understand when you have no programming background.