Hindsight bias is a term used in psychology to explain the tendency of people to overestimate their ability to have predicted an outcome that could not possibly have been predicted. In essence, the hindsight bias is sort of like saying "I knew it!" when an outcome (either expected or unexpected) occurs - and the belief that one actually predicted it correctly.
Here are some examples of the hindsight bias phenomenon.
Now you have lots of examples of hindsight bias from everyday situations. If hindsight bias is something you or people you know engage in, you'll be better able to recognize this phenomenon in the future.