The other day at the office, I was the only one that had heard of, let alone used, Slackware. I am also the oldest in the team, this is probably no coincidence.
It is my clear impression that many Windows users would be hard pressed to explain what 'Windows' is and does.
I"m starting to realize where so many holes in my understanding exist, and abhor how for so long I was just content to accept most things in Windows just happened.
Then I started actually digging into log files and various software distro's and tried to connect all the dots.
Long story short, nothing scares me more now than a computer program that I can't explain why it's doing what it's doing. SystemD falls into that trap for me. It may just be a case of sitting down and reverse engineering it until it clicks, but until then, I'd rather not trust anything important to it.