Why there? Why aren’t we prevented from having the great idea in the first place?
Because thinking is imaginary.
Writing creates reality.
The reality, of course, of our own belief. Just as we see, hear, and feel with our brain, not our eyes, ears, or fingers, we don’t experience reality outside of ourselves, we experience inside our heads.
And our heads are very very good at knowing the difference between imaginary and real. Planning a crime we’ll never commit, in order to write a story, fires very different portions of our brain than, for instance, remembering the time we actually stole something from the five and dime.