My friend and I were discussing a very similar topic not too long ago when I dropped by his place, though it was more along the lines of being our own worst critics, and grudgingly accepting a "good enough" result while seeing all the bits where we could have fixed it and trying to keep them in mind for "next time".
We were talking about completely different fields too, so I guess some things are universal truths XD
I think there's a great deal of importance in understanding what went wrong and dealing with those things to work towards a better result for next time; doing the same thing and expecting different results is a rather bonkers thing to do.