I remember 40 years ago I took a piece of my art to a frame shop.  It was a watercolor.  The frame shop owner tossed the painting on the floor to look at it.  Being new at art, I thought that was some kind of an art world thing.  I later learned there are different ways to look at your work to study it for errors like hold your painting up to a mirror or looking at it upside down.  In any case, lately I try to not get into to big of a hurry to say a painting is finished.  At least for me, at times I may become too easily satisfied with the painting I called finished.  It pays to study it over and over again after we think a painting is finished.  An even better painting may result in pausing before we put it out for others to see.  Finished? It is a good question, I believe.