I mean use of the CLI on Linux generally. I used "terminal" vaguely because the original comment used it vaguely. "Down pat" is to say that I'm perfectly comfortable with it, namely that the course taught me:
- How to execute programs from the shell (and interrupt execution/kill processes).
- How to navigate and alter the filesystem, search for files and their contents, etc.
- How to install, remove, and configure software.
- How to set aliases.
- How to write shell scripts.
- How to edit files (although 99% of the time this is useless; I'll just use something like Kate instead).
- How to parse and interpret program output.
- How to read man pages.
- Generally how to do anything I couldn't/wouldn't prefer to do from a GUI instead.
I use the shell vastly more than 99.99% of people and haven't had a problem with or changed how I interact with it since that course; that to me is "down pat" for the terminal itself. I don't care if I don't know every application and flag ever made, because that's not the point β like knowing how to use a GUI doesn't mean you've memorized all GUI software, just that you know how to interpret the design language of and successfully use new GUI software. If I need to do something my current tools can't, I can just search for the right program and use the man page to quickly write a command.
Meanwhile, with something like LibreOffice Calc, which I understand is much less feature-rich than the industry standard Excel, I don't just learn about new functions like CORREL(), akin to what I said before about learning new CLI applications; I fundamentally learn how to create and edit spreadsheets more quickly. In Impress, I still learn how to make presentations more appealing, more readable, etc. Basically things that aren't just rote memorization of gadgets that I could look up at any time. That's what sets it apart to me β the fact that anything I don't already know about the Linux terminal is present in readily available reference material and better off not memorized.