Often good work is stymied by ineffective process. That's why reflection and revision are so important. It's important to look at work that doesn't meet the expected criteria, and redirect that work.
For example, today I wrote an email that was misconstrued. I didn't mean any disrespect, but in hindsight and with rereading the email, I could see how some may have read it that way. So, in the future I'll write in a more concise, direct way leaving little room for misunderstanding. We all err, and what's important is to look at the error, and make good change.
Good teachers are always reflecting about their efforts and practice. They teach, then reflect, revise, and teach again. Our good work is spiraling work towards better and better practice. Without that reflection, our work become stagnant and similar errors happen again and again with no resolve or betterment. Without reflection, it's difficult for us to get better or solve problems, and there's less enthusiasm for efforts that aren't directed towards betterment.
The past always has lots of good to pull from and weave into the future, but to work only as we have in the past is not to grow and develop--that growth and development is integral to good teaching and good schools.
So today's mistake is tomorrow's betterment--I'll make the change noted, and think about the processes that support good work and effort going forward.