Most small businesses come about because a technician (say a carpenter, plumber, dentist, graphic designer) gets an idea that instead of continuing to do what they do for someone else, they will start their own business and keep all of the lovely cash that was previously lining the pockets of their employer while they were paid the same salary regardless of how much value they brought to the business.
The Top 100 Business Schools avoid this piece of critical thinking in their MBA programs, dismissing it as too soft and somewhat less than tangible. Try telling that to Nordstrom. 10 Minute MBA creator John Quinn explains why entrepreneurs and business leaders need to develop their own version of his Theory of Everything
A touchy subject this, but unfortunately there are many key things about being successful in business that you won't learn in Business School. One of the worst omissions in my view is that of the power of small changes and how these compound to make big improvements to business over remarkably short timescales. One such idea is the one I call my magic profit spell, which shows you how to take specific components of any business and make them unrecognisably better by changing things almost imperceptibly.