My teacher is always encouraging us to embrace mistakes with “There is no such thing as a mistake”. I think this is pretty wise teaching, up to a point. :) There are definitely some things I’ve done that are not fixable except by starting over. Yet I don’t “bin” the bad painting, but put it up in the stack with everything else. It’s possible its time has not yet come, or I may find something else that will work; if nothing else, I can always use the back side of the paper for a value study or an exercise.
In my time spent consulting with people, one of the phrases I often used was that there are no mistakes, simply lessons whose teaching has not yet been fully absorbed.