Back in the art gallery in London where the boards are on display, the same message resonates. One board is dedicated to Evel Knievel, the daredevil stuntman who Gregor quotes: "If you fall during your life, it doesn't matter. You're never a failure as long as you try to get up."
Gregor says even skateboards' makeup is a metaphor for resilience. "They are always made of maple," he explains. "It's the hardest wood; it flexes. You land with a certain impact and it bounces back."
The etched boards have helped Gregor heal his personal pain. Through Skateistan, they're also bringing learning and fun to children who desperately need it.
Humble & Epic is on display at London's Herrick Gallery until December 19, with plans to exhibit in Tokyo and Seoul in 2016.