I disagree with this. If you have a GUI, sure, you have fun buttons to click. But if you don't understand what those buttons actually do, you will mess things up if you click them without thinking. The solution to this is to read the documentation and understand what you are doing.

If you don't have a GUI, then you will have to read the manual to find out what to do.

The end result is the same; you have to read the manual.

(Also, you can have discoverable interfaces without graphics. Open a file in Emacs and type M-x describe-mode. From there, you have a description of the commands available, and links to follow for more details about any aspect.)