Stamping and Embossing

and facial piercing or stretchers (usually trends associated with 'scene' people)

I mean I don't see any appeal in permanently getting ink on your skin in a most of the time ugly design, I can understand why someone may want a tattoo as a tribute to a person or place, or as a memory (like the guy in Memento) but some people just get tattoo's for what seem's no apparent reason. why? and why do people insist on have piercings all over their face or stretchers in their ears?

I know some of you are going to say to 'be unique' but with a population on Earth way over 6 billion the amount of people who do these things to their body it's certainly not unique (nothing is really) and with all the different designs you can get most people end up with the same or similar. so why?