People can shed as many as 500 million cells of skin every day, yet tattoos remain for a lifetime. Why is it that a bad sunburn will peel, fade, and become a distant memory, but you still have to explain that Chinese symbol you got on Spring Break to your grandchildren?
Check out this video by Claudia Aguirre of TED-Ed, explaining the long history of tattoos in human cultures, and what makes them a permanent part of our bodies.
Also, be sure to check out this amazing video of the tattooing process, close up and in slow motion.