why permanent tattoos?

how come a lot of people get permanent tattoos? wouldn't it hurt just to get it done? once, at whole foods market, i saw a man with tattoos all around his arm. it was practically covering it! another time, a man in a pick-up truck had his are hanging out of the window. his arm had a big tattoo on it, and i think it was a snake. my swimming coach has a tattoo on his shoulder, and it's scary whenever he takes off his shirt. whenever i grow up, i am not going to spend money on a permanent tattoo.