Ouch!
I've done it before so I know how it feels!
I had 3 nails go into my foot at once. I was younger, probably around 11 or so. In Michigan playing with my aunt's neighbor kids in their backyard. There was an old piece of wood with nails sticking out of it in the middle fo the yard. I ws running and had flip-flops on. Luckily, the flip flops stopped them from going in too far.