In 1990s, self-interested market participants pined to assume away the physics of power systems and have ‘simpler’ markets. They argued that a market that honors the physics unnecessarily complicates markets. In an effort to make the market ‘easier’, we created fictions to make the market easier and broader. But you can't fool Mother Nature, we now know empirically that the simple market is easier to manipulate and to date, the easier markets have failed. Evidence points to complexity for efficient commitment and dispatch. Since fictions are necessary because we cannot yet solve the more complicated market model with more physics. Care must be taken in creating fictions. In power systems, bad fictions can lead to cascading blackouts that are disruptive and very expensive. In ISOs, Complexity and Simplification co-exist. The day-ahead market and real-time market contain the necessary complexity to solve the complex operations problems. Financial market exists for those who want simplicity.