In Voltaire's Dictionnaire Philosophique, he wrote, "Le mieux est l'ennemi du bien." The best is the enemy of good, or, less literally, the perfect is the enemy of the good.
And Gen. George S. Patton is reputed to have said, "A good plan violently executed today is far and away better than a perfect plan next week."
Two quotes I return to over and over again, in my work and every other aspect of life. In our search for perfection, how often we miss the opportunity to "violently execute" (or at least vigorously implement) a plan right now that would be more than good enough.