Dikembe Mutombo may have an easy smile and famous gravelly laugh, but the NBA Hall of Famer does not mess around.
"That African boy does not know how to play basketball," Mutombo recalls naysayers claiming when he was drafted by the Denver Nuggets fourth overall in 1991, according to NBC News.
The Georgetown graduate proved them wrong and went on to become an eight-time all-star and one of most celebrated defensive players in the sport's history.
Mutombo retired in 2009, and traded in his jersey for expensive blue suits. His mission is now saving and improving lives, not blocking shots, and he's using his stature and fame to help some of the world's poorest and most vulnerable — including building a state-of-the-art hospital to help the poor and sick in his native Democratic Republic of Congo that Mutombo says people told him he was "crazy" for attempting.