Because your brain evolved to learn quickly from bad experiences, but slowly from good ones.

You can change this.

Life isn't easy, and having a brain wired to take in the bad and ignore the good makes us worried, irritated, and stressed, instead of confident, secure, and happy. But each day is filled with opportunities to build inner strengths and Dr. Rick Hanson, an acclaimed clinical psychologist, shows what you can do to override the brain's default pessimism....