Your passion for a product, like Shaquille O'Neal's for Auntie Anne's pretzels, is a starting point for research, not a reason to invest. You must separate personal enjoyment from objective financial analysis, as even beloved brands can be poor investments if the business fundamentals are weak.
To practically "invest in what you know," first analyze your credit card data to identify where you spend more than average. Then, listen to those companies' quarterly earnings calls, where CEOs are legally required to discuss both positive and negative results, offering unfiltered insights for potential investors.
The "invest in what you know" philosophy extends beyond consumer habits to your professional life. An oil worker inherently understands the energy industry better than a restaurant manager, and vice-versa. This specialized knowledge from your career is a powerful, often overlooked, starting point for identifying investment opportunities.
Shaq's involvement with the fraudulent crypto company FTX, which he admittedly didn't understand, directly violated his primary rule of investing only in what he knows. This led to a significant loss and legal issues, demonstrating that disciplined adherence to a strategy is just as crucial as the strategy itself.