What Do You Need to Learn to be a WordPress Expert?

In “Wanna Create Dynamic Websites? Learn JavaScript” by Daily Blog Tips, Daniel Scocco says:

If you want to become an expert programmer and make a living developing software you’ll need to learn a wide range of stuff, from logic gates to how the hardware works, from algorithms to data structures and programming paradigms (if this is actually what you are looking for I suggest you peek at the curriculum of the Computer Science degree on some good university and follow along).

Luckily, Clark College’s degrees for Web Development, Web Programming, and Computer Graphics Technology degrees include the skills you need.

What do you need to learn to be a WordPress expert?