There are other products out there that put automatic changes on the undo stack. I regularly encounter this behaviour in Visual Studio: pasting code in the edit

There are other products out there that put automatic changes on the undo stack. I regularly encounter this behaviour in Visual Studio: pasting code in the editor is decomposed into pasting text and reformatting it. So the first Ctrl-Z reverts the code to the exact text you copied. The second Ctrl-Z will remove it.