A feeling of guilt of not doing as well as you think you did, feels bad, right? I've experienced it, so don't worry, because almost everyone is doing it. But the question is, when your doing something that is not as excellent as you think it will be, and in your thoughts it only achieved good, is it the same as doing great?
Doing good and doing great is a very different things. People who only do good will never improve, while great people tend to improve more. Why? Because great people are very competitive, and if they know that they have a competitor they will always have to improve in any way they can, so that their competitors will always be left behind. Imagine, would a racer who has a world record lose to some other guy? No! He will improve his engines, increase handling, anything to keep the others from beating him. Good people actually is pleased by what they have done, and refuse to improve, leaving his competitors to pass by him. So, what type are you?