Some of the advices might be true here. But if you really want to understand how programming and computers really work together, you should learn Assembly language, at first you might be scared of it, because a lot people think it's the holy grail of programming languages, and they think that only best of the best can learn it.
While it might have some some truth to it, but even knowing a little bit of Assembly will help you A LOT! I was learning assembly for a month or so (I just really wanted to try it out), and I already understand better how linker works, how everything is compiled, how exactly stack works, where passed arguments go, memory management, and all that stuff. I can even write my own simple x86 kernel!
So if you want to get started, download or buy a book called "Assembly Language Step by Step". It is meant for total newbies who want to learn Assembly as a first language, and he has some good points on why one should learn Assembly as first language, and not Python or Java as other people tell you.
I promise, you will gain a better understanding of programming langues and deep C.
Afterwards you might even want to disassemble your C code and read it in Assembly to better understand how things work inside.
Also, I checked out those slides, I saw few parts where it talked about registers, data segment, and other stuff I wouldn't probably have known before reading book on assembly.
So go learn some Assembly and good luck with your learning!