A woman climbed on the bathroom scale after two weeks of butterless toast and chilly jogs around the park. The needle was still stuck on the number where she'd started. This struck her as typical of how things had been going lately. She was destined never to be happy.

As she dressed, scowling at her tight jeans, she found $20 in her pocket. Then her sister called with a funny story. When she hurried out to the car angry that she had to get gas she discovered her roommate had already filled the tank for her. And this was a woman who thought she'd never be happy.

Every day, it seems, we're flooded with pop-psych advice about happiness. The relentless message is that there's something we're supposed to do to be happy make the right choices, or have the right set of beliefs about ourselves. …