Brendan Marrocco's no stranger to NASCAR.
The former U.S. Army sergeant developed a close relationship with Brad Keselowski during the 2012 Sprint Cup Series champion's visits to the Walter Reed National Military Medical Center, where Marrocco spent time recovering after being struck by an explosive projectile while serving in Iraq in 2009. Marrocco lost all four limbs in the incident, but became just the seventh American to undergo a successful double-hand transplant.
Fast forward to February 2014.
Kurt Busch, who recently announced that he would be rolling the efforts of his Kurt Busch Foundation into the Armed Forces Foundation and is perhaps the sport's biggest proponent of care for wounded veterans, was also on hand for last September's trip to Walter Reed. He took note of Marrocco and invited him to attend this year's Daytona 500 as his special guest.
David Letterman had Marrocco on the "Late Show" on Monday to talk about his time in Daytona and his recovery -- including learning how to drive a car again.
"Kurt Busch dedicated the race to me," Marrocco told Letterman. "Kurt and the Armed Forces Foundation had me down there with one of my buddies."
Marrocco went on to explain just what the whole experience felt like for him, which exuded an extended ovation from the crowd and a classic response from Letterman.
"We were on the starting grid, and they were doing the opening ceremonies for the race and singing the national anthem," Marrocco said. "All of a sudden I realized to myself that I'm holding my hand over my heart and I completely just zoned out and said, 'How (expletive) cool is this?'"
To which Letterman responded, "It is very (expletive) cool."
Watch the clip of Marrocco on Letterman: