This is an interesting article called “Beware the Winning Streak”.  Essentially, it points out the obvious, which is that it gets harder and harder to improve performance the better your performance is.  As one of my people used to tell me… “Happiness is a low base.”

I see this concept come up often: it’s usually the reason why you don’t aim for 100% targets on your performance standards. If you’re at 90%, it gets very expensive and much more difficult to chase down the final 10% to hit 100%.

For people, I think you can keep striving to get it right. But you shouldn’t feel bad if you’re not perfect. Some things don’t matter as much as others.  Some things have to be 100% (responses to 911 calls for example). But not everything. Just make sure you pick the right things.