I think complex creative blocks can begin in simple ways.
My greatest block began on my first day of Art college. The Instructor stands in the center of our easel-filled class, stares us all down, carefully picks up a piece of paper, crumples it into a ball, and tosses it on the floor. He takes a drag of his cigarette, adjusts his sunglasses, and says "draw this paper until lunch time."
The next few hours were harrowing-- the sense of having to get it right, having to include every detail of the ball of paper right. I was in the middle of a class of illustrators and artists from all over the world, and my drawing skills were decent, but not Rembrandt-level, and there were a lot of young Rembrandts in class. The sense of competition, the tension in the room, at least for me, was palpable.
From that experience, and my art college years, I grew up believing that the creation of art was a serious, strained process, wrought with detail getting the line, shadow or grammar perfect.
And the fruit of this belief bore very little art.