If you are 50 or older, or plan to be some day, here's a fact you may find surprising. Working, rather than retiring, will enrich your life and fulfill your dreams, particularly if it is work that taps what you're really good at and feels like its own reward. You owe it to yourself to discover work that satisfies all those requirements.

Millions of mature people are beginning to realize this fact, according to AARP surveys of those at, or approaching, retirement age. They are redefining retirement, perhaps even abolishing the concept, with a creativity and passion once considered the domain of much younger folks. And that is a change all of us -- politicians, the business community, the health care industry, and everyone who cares about a successful future -- should be celebrating.

Our jobs determine to a large extent what our lives are like, says Mihaly Csikszentmihalyi, best-selling author of Flow and professor at the Drucker School of Management at Claremont Graduate University. Not surprising then, most of us want to do good work, make a contribution to the lives of others, feel proud of what we do, and know we are being compensated and treated fairly. Reasonable expectation for an activity that claims many, if not most, of our waking hours, wouldn't you say?

But there are other benefits of work that are equally important, especially at mid-life and beyond. So here are five good reasons you should seek out work you love and keep on working.

1. Enjoyable work is the best health maintenance strategy available, not to mention life-extender. Our brains need interesting challenges and tasks that connect us to the whole of life, throughout our lives. (The crossword puzzle and taking up juggling don't cut it.) Healthy mind, healthy body.

2. The Money. It may seem obvious, but the truth is, a paycheck is one of the major satisfactions of working. It is certainly the best way to free yourself from the specter of 'running out of money' in your later years, a common fear among older people.

3. Work provides you with community, social connections, new ideas, the opportunity to stretch and grow, and limitless creativity that nothing else can. A good life needs all of these.

4. Work enables us to express unique talents and skills, discover who we are and why we are here. According to Roper Research: Fulfilling work has become a core universal value alongside family, freedom, love and health.

5. Everyone is needed. With many experts predicting a global labor shortage in the near future, we can't spare anyone. Each of us has something of value to contribute and a need to give. And there is, and always will be, more work than people to do it.