Facebook, YouTube and the iPhone . Three things that no longer feel new at all, yet none of them existed when LeBron James made his NBA debut on Oct. 29, 2003. His son Bronny James, now his teammate, had not even been born yet. LeBron is far more than a battle-tested veteran or simply the oldest player in the league. His career has transcended time itself , to the point that the very meaning of longevity has been redefined by "the King." Now beginning his 23rd season , still a starter and still a key piece on one of the NBA's best teams , the obvious question remains: where is the limit? Just last season, in what was his 22nd year, LeBron averaged 24.4 points, 7.8 reboun ds and 8.2 assists per game . Those numbers are unprecedented for a player more than two decades into his career and not far off his lifetime averages. Consistency may sound like a dull word, but there is nothing simple about maintaining elite production for more than 20 years. No one else has don...