I just find certain things to be quicker in the terminal than doing it through a GUI.
Like installing software. I think it’s quicker and more direct to do something like sudo pacman -S Firefox than to go through a gui. Especially if Im using a drop down terminal that I have hot keyed.
As for remembering everything, I’d say it’s just a matter of experience. Like, you had to learn how to use a GUI app at one point or another.