All of the mentioned points are very good (and applicable) to performing the job properly. But for me it is a matter of curiosity. If I need a function to work,

All of the mentioned points are very good (and applicable) to performing the job properly. But for me it is a matter of curiosity. If I need a function to work, I want to know how it works. If I need an application installed, I want to know its underlying pieces, how it communicates, what dependencies it has, etc. At some point you have to draw the line of course, as it is impossible to know everything, but that line is generally easy to find. For example, I could put you to sleep talking on how TLS handshakes work, but I have no interest or desire in learning the math behind any used algorithms (although I do keep abreast of security issues with ciphers, etc.). Learning new options (say the proliferation of systemd in linux land) is always good, even if you ultimately decide not to implement it at this point in time. So just keep learning, always find new ways to do things, audit your own systems, etc.