Tattoos and body markings can mean all manner of different things to different people. What is celebrated in one part of the world can be viewed as inappropriate somewhere else; a sigil or illustration that has significant meaning in one place might look like random squiggles in another.
I think it’s safe to assume that human beings have been expressing themselves and promoting messages through their appearances for about as long as we’ve been around as a species.
I don’t know about you, but I find it particularly interesting when I see the same tattoo on a number of different people. That is to say I’m instantly intrigued as to what the tattoo in question means, and just why the person in question thought it was so important that they wanted to wear it as a visible marker for the rest of their lives.