That's the mouse generation (pun not intended!). They are used to work with only the mouse and forget that every software can also be run with key combinations. I work a lot with key-commands as they often are quicker than the mouse.
I have a list of commands on my pinboard, just in case. And I recommend printing a list of the beep-codes. That's incredibly handy as often when you get an alarm-beep from your computer, it is not able anymore to go online and google the respective code's meaning. Btw, whoever came up with the beep code was a genius! The computer literally tells us what's wrong with it. They just need to introduce a new code for "cat sitting on the keyboard"