Creativity is not something you possess, but someting that expresses through you. You might call that something “inspiration.” The point is, you need to step aside and allow this force to enter.
Puccini claimed the ideas for Madame Butterfly were dictated to him by God. I myself have often sensed “higher forces” of inspiration. I sometimes think of ideas as coming from art itself. I went through a period for several years when I conceptualized this as “angels” of music, of painting, of theater, etc. In this sense, music itself wants some music written and we are merely the conduit.
It certainly sucks the ego out of things, doesn’t it?