It's been 45 years since the first graduating class of the modern era, and many of those members of those early classes are entering retirement age. But that doesn't mean most of them are stopping. For one, "retirement" means seeing patients 5-6 days per month; another has moved to nonclinical work such as editing medical journals. We spoke to a few of those early class members about the concept of retiring -- and what they're still doing to stay busy.