Our brains are prone to cognitive biases that cause irrational and illogical decision-making. Design thinking and lean startup methods help overcome these biases by emphasizing evidence-based learning through experimentation and measurement of user behavior rather than opinions. These methods instruct companies to build products, measure user data, learn from it, and pivot as needed to scale successfully like Coinstar and Zappos, which relied on prototyping, A/B testing, and other techniques to develop the right solutions for customers.