Can anyone explain to me the NEED to pierce or tatoo their bodies ; either than for, vanity or just to be cool

It is not a NEED, and it is not for vanity or "just to be cool".

For me being pierced was, 1.) for sexual stimulation 2.) a bonding experience 3.) to just experience a new sensation. I went with a friend who was by my side the entire time, and I also now know what it feels like to be pierced in several places.

There are some people that like to tattoo their bodies as a token of respect or in remembrance of someone or something.

There is NO NEED to pierce or tattoo your body. You have to WANT to do it first. I don't know why people pierce their bodies...some just like the way it feels. In other cultures its sort of a ritualistic thing to do these things.

I won't argue with the fact that some people do it because they think its cool. These are the people that are stupid enough to get the tattoos and then pay for them to be removed when they realize that it was a stupid idea.

A lot of people just like body art. I love body art, it is an extreme way of expressing yourself. There is nothing wrong with it, and there are really awesome tattoo pieces out there. Sure, some people may get it to be cool, but that's lame anyway. Expression of ones self is why I have them

I don't think anyone NEEDS too, some do it for attention, others because they like the way it looks or makes them feel about themselves. I think lots of people get them because of the experience involved. For example I got a matching tattoo with my best friend. Every time I see it I remember how spontaneous it was, my friend of course and the time we spent together in NYC. It will always mean something different for everyone.

Nerve stimulation.