Why do we not have an Option to Exit without Saving? If you totally mess up an image by doing something irreversible, you cannot exit without Saving that. In trying to find a way to eliminate an experimental series of adjustments, filters, etc that I no longer wanted to keep, and certainly did not want cluttering up my History and reducing the number of Undos available, I also experimented with Revert. It will do what I was hoping, which is take you back to the step you clicked on. Including all the way to the original first layer! Problem solved. Except that Revert is irreversible. And there's no way to get out of that situation without Saving, which overwrites the home screen image. Perhaps what I did was stupid but it should not have been fatal. And it should not be necessary to first duplicate every image you want to work on, just in case you make an irreversible move.