I'd like to learn about
apt-get so nothing bad can surprise me. I was looking for some tutorials but have found nothing that teaches it carefully including its internals. I found this article but it's insufficient for me.
Where can I learn more (excluding documentation and manual pages)?
Mastering here does not mean that I will learn 100 switches of the
apt-get command but it means that I will learn how it works on some more general level than reading its source code.