Ctrl + Z (Undo)
The greatest benefit of using computer will be "Undo" the work easily.
There will be no other function being used so often. This is a common command that is invariably equipped in most graphic software, text editing software, and many other programs.
And regardless of software manufacturer, the common shortcut key for "Undo" is "Ctrl + Z".
Place your hand that doesn't handle a mouse or pen on the keyboard, and try to use "Ctrl + Z" shortcut key instead of going to the menu. You may feel strange at first. Once you get used to it, this is very useful and convenient. And you can use this shortcut key to most software.