Scientific Theory of Management by Frederick Taylor, which had factory managers breaking down tasks into small pieces, forcing their workers to specialize, and financially incentivizing them to complete those tasks efficiently. It was a brute force method, but it worked pretty well.

I don’t know what’s the matter with people: they don’t learn by understanding; they learn by some other way — by rote or something. Their knowledge is so fragile!
Richard Feynman1

Self-confidence is what empowers you to execute difficult decisions and develop self-knowledge. While the ego tries to prevent you from acknowledging any deficiencies you may have,