（Daniel Gilbert）出版過一本著名的書《快樂為什麼不幸福？》（Stumbling on Happiness， - Annie Duke

Success does not lie in sticking to things. It lies in picking the right thing to stick to and quitting the rest.

when we quit things, we usually follow the idiom out of sight, out of mind. We don't naturally track things that we're no longer in. This is likely what is causing the problem with the portfolio managers. When they enter into a position, they're tracking that every day, because it's part of the portfolio. But once they exit, they're not tracking it in the same way, because the position is now off their books. It's no longer part of their P&L statement, not as far as they can see in any obvious way.

Goals can make it possible to achieve worthwhile things, but goals can also increase the chances that we will escalate commitment when we should quit. Goals are pass-fail in nature. You either reach the finish line or you don't, and progress along the way matters very little. Don't just measure whether you hit the goal, ask what you have achieved and learned along the way. Set intermediate goals and prioritize goals that allow you to recognize progress along the way or acquire something valuable even if you don't reach the goal. Goals, when set, are a proxy for an expected-value equation, balancing the benefits that you're trying to gain against the costs you're willing to bear. Inflexible goals aren't a good fit for a flexible world. With better advance planning (like identifying monkeys and pedestals and kill criteria) and the help of a good quitting coach, you can make goals more flexible, setting at least one "unless" and planning regular check-ins on the analysis that initially led to setting the goal. In general, when we quit, we fear two things: that we've failed and that we've wasted our time, effort, or money. Waste is a forward-looking problem, not a backward-looking one. ACKNOWLEDGMENTS