Good work requires a lot of devoted time. Even if the area is one of your expertise.
I had to think about this, as I am undertaking (as a student) a intermediate python course online along with my friend Avinash. Since I know the concepts well, I usually do not listen to the lectures and jump directly to exercises and quizzes. We have to a mini-project every week and I plan just enough time to complete the project. It is not just time, but I think, I plan for just enough motivation to complete the project by deadline.
In the Pong game project, I had scored 2 points less than others peers, for whom I had given full credit. If I think, why should I score less in peer evaluation, it occurs to me that I am not patient enough with the project and I am not patient to complete it fully to everyone's satisfaction even though I might be fully capable of doing so. Quite a realization. It will be good if I do something about it.