Seniors who stay active mentally may be able to help keep their mind sharp longer. "When it comes to brain power, much like your muscles, the 'use it or lose it' concept applies," says Dana Anspach, CEO and founder of Sensible Money in Scottsdale, Arizona. "Retirees who engage in life-long learning keep their brain engaged by challenging themselves to learn new skills. It's important to find things you're curious about and dive in. And in retirement, you have the time to do it." Taking classes in retirement can also be a way to meet new people with similar interests and socialize. "You can go lots of places to learn. You can purchase CDs or DVDs. You can learn from great teachers," Frank says. "We have a sense of community. You will meet people in classroom and continue conversing after class. We're all teaching and learning together." Some colleges, including Pennsylvania State University and Colorado State University, allow seniors to audit classes tuition-free. Other universities, such as Boston University and Georgetown University in the District of Columbia, charge a flat fee to retirees who audit classes, such as $50. Many state university systems allow retiree residents above a certain age, usually 60 or 65, to take for-credit classes. Community colleges may also offer low- or no-cost programs for retirees. Psychiatrist and consumer health expert Janet Taylor says people who continue to learn in retirement are among