Duncan grew up in St. Croix in the U.S. Virgin Islands, so he was not on the radar of American media like many young basketball stars.
Duncan didn't even start playing basketball until ninth grade. Prior to that he had dreams of becoming an Olympic swimmer and was a top U.S. junior swimmer in the 400 freestyle.
When Hurricane Hugo destroyed his local pool in 1989, Duncan was forced to practice in the ocean. He later said swimming lost its appeal because there were no competitions at this time.
This is the court where Duncan's high school basketball team played games.
The rims weren't even ten feet high, so it is easy to see why he flew under the radar.
Duncan played in the hoops-heavy ACC, but Wake Forest was in the shadow of other schools.
He was one of the last college stars to stay in college for four seasons.
And by the time he did go pro, the NBA was in a youth movement with high schoolers like Kevin Garnett and Kobe Bryant going straight to the NBA. Duncan was an old man by comparison.
And there was some public backlash against Spurs for being able to draft Duncan just because David Robinson was injured for most of the year before, creating a super team.
While most stars gravitate towards big markets, Duncan played his entire career in just the 36th biggest television market, San Antonio.
But Duncan has never sought the bright lights and has made plenty of money playing for the Spurs, earning $239.7 million in his career.
Duncan didn't get a lot of credit for his first championship since many felt the Spurs only won because Michael Jordan retired the year before after winning his sixth championship with the Bulls.
And his second ring only came after the Lakers three-peat and the Kobe Bryant-Shaquille O'Neal tandem was starting to fade.
And the Spurs' third and fourth titles came before the NBA's recent renaissance led by stars such as LeBron James and Kevin Durant.
Duncan has made as much as $22.2 million in salary in a single season, but has never made much off the court.
During the 2011-12 season, Duncan made just $2 million in endorsements. That same year, LeBron James made $40 million in endorsements.
He has done commercials, but like this one for Nike back in 2000, he was often just a co-star
Late in his career, Duncan became the NBA's no-nonsense, anti-hipster hero who wore whatever he wanted.
It wasn't until Duncan won his fifth NBA championship with the Spurs in 2014 that it seemed like he finally started getting the respect his career deserved.
Now check out who won the NBA offseason.
