[user104658]

I'm guessing he didn't actually nail through his testicles, just the scrotum... Which actually has very few nerve endings so wouldnt have hurt much.

Before my 6th year prom, aged 18, I decided to do a bit of "manscaping" and accidentally cut a 0.5cm hole in my ballsack. True story! Barely felt it but oh god the panic... Hahaha. Turns out scrotum also heals like wolverine?? It had healed over completely in 36 hours.