David Smith of Santa Clara, Calif. was leading a rather normal life in 2006. The Morgan Hill native worked the graveyard shift stocking shelves for a grocer and then spent his mornings driving his children to school. In between, he obsessed over the San Francisco 49ers. Since his high school days in 1978, in fact, he missed only two home games at Candlestick Park, the weeks that his father and father-in-law passed away. Then the organization's human resources department, which had Smith's resume on file from a job fair he attended, called him in for an interview. They wanted to test his nose...