SAN ANTONIO — If the same rules applied in this brief Tim Duncan interview that were in place in 2007 when the San Antonio Spurs forward was so famously ejected from a game for the simple act of laughing, then this would be a technical foul. "The Big Stoic," "The Big Recluse" or — if you care for the classics — "The Big Fundamental" has agreed to field two questions about his latest Father Time-defying feats. And the first query about how he's doing it — "What drives you at this point in your career?" — inspired a smirk that, much like the secrets to his remarkable season, will go unexplained. And the answer, as is almost always the case when it comes to him, isn't nearly as compelling as his one-of-a-kind career.