This part was really confusing and disappointing for me.

In the real world, you would refactor using the same general ideas instead of leaving the code as-is. I think this is one of the fundamental ideas in OOP to grasp. Maybe one of the biggest hurdles to clear in order to progress past script / markup languages. It's a challenge, but the "aha!" payoff is worth it. Plus, I think if you can grasp it, then it opens the door to idiomatic programming ideas / design patterns / and other abstract ways of thinking about how to solve problems as a programmer. When you read that programmers end up learning way more than one language, it's because they're all pretty similar and refactoring code into functions and objects is a big part of it. On the other hand, simpler things like wordpress will not require this sort of thing and you can definitely make a living with a simpler combination of wordpress, PHP, and SQL.

This video was pretty confusing to me too. Although I do understand the basic concept of what he's trying to say, the pace seems to have stepped up to triple, rushing over very important and reasonably complex concepts.

Also, although the code is shorter c.q. takes up less characters (does that speed up the code significantly?), for a beginning programmer like me it's actually MUCH harder to read. Instead of understanding what each line of code does, I now have to go back to every function and decrypt the syntax, to decypher what it actually does...

I can understand that for an advanced programmer, this makes perfect sense. But if I were to see this code fresh out the box, I'm not shure I would be able to decrypt it and understand what it does, at all... I guess I still have a long road ahead of me...

Yeah, I agree that it was a bit confusing. I think the positives are that the code is easier maintained, especially if you are working with other people or have to change your code in the future. There is a huge difference in coding alone in a text editor and in a project with other people.