Most people have heard of the Y2K problem. But recently, I found myself thinking about a different problem altogether. I call it the W2K problem. W2K stands for a surprisingly simple but unsettling idea: the average person may have only around 1800 to 2000 truly productive working weeks in an entire career. At first, the number sounds absurdly small. But the arithmetic is straightforward. A person who begins serious professional work around the age of twenty-five and retire