A while ago, I was serving a smart engineer as her people leader. She was very excited when given a new project but started complaining after a couple of weeks by saying "This is so boring".
I realized that she is a fast learner and mastered the new skill required in the project very fast. I challenged her to improve what she was doing and guess what happened?
She got excited again!
This is not rocket science, its Shu Ha Ri in action.
Shu - to master
Ha - to improvise
Ri - to create