It barely touched the complex stuff yet, I'm afraid!
But I'm happy to clear up at least some misconceptions

I always wanted to write a "How CPUs work, from a developers perspective" kind of blogpost which goes into the nitty gritty detailed stuff that one might want to be aware of for performance sakes, but I'm really bad at explaining stuff because I love to assume that people just know things already or get all bits skimmed over from the context. I might do that one day though, and it's going to be a very very long blogpost.

But I can only strongly suggest everyone to get at least a high level overview of these things. There are a lot of things that may appear counter intuitive that result in better performance and sometimes a small change will result in a heavy performance hit for no obvious reason at all until you take a look at it from the CPUs perspective. Of course, modern CPUs have enough power to just mask this, but especially games with a really tight performance budget will run into these things. Also, it's a ton of fun to learn new things.