"But I thought perfect was good," I hear you say. Not always. The dictionary definition of excellence is "to surpass", it is "the quality of being outstanding or extremely good". So, when you strive for excellence, you are always looking at where you are and how you get a little bit better. On the other hand, when you strive for perfection, you are aiming at something that is so good that it cannot get any better and the risk is that you will never get there.