Have you ever invested time in something that, with hindsight, just wasn't worth it? Overpayed in an Ebay auction? Continued doing something you knew was bad for you? Sold stocks too late, or too early? Taken credit for success, but blamed failure on external circumstances? Backed the wrong horse? These are examples of cognitive biases, simple errors we all make in our day-to-day thinking. But by knowing what they are and how to spot them, we can avoid them and make better choices - whether dealing with a personal problem or a business negotiation; trying to save money or make money.