Human thinking relies on mental shortcuts that work well most of the time but reliably distort judgment in specific, predictable situations. This course walks through the cognitive biases most likely to show up in ordinary decisions — what to buy, when to quit a project, who to trust, how to read a situation — using plain, well-established psychology concepts rather than technical jargon or citations to specific studies. Each lesson explains how a bias operates, where it commonly shows up in daily life, and gives you a concrete habit for catching and correcting it before it quietly steers a decision you will later regret.