Tattoos

I am inked. I have a tattoo of Quintessence within Alchemical Silver, with plans for many more pieces of ink. One of the pieces I want is a tribute to my dog, Cody, who passed away last April. I'll get it on my calf, since that has more room, which means a bigger piece. I'm also planning a massive back piece that encompases the vast majority of my favorite Transformers, and which will carry over onto my right arm, and possibly even onto my sides. I'm also planning out a 'spark' for over my heart. It's like with potato chips. Can't stop at one... but they all tell a story. I have many tattoo ideas for things like moving into my own place, completing 60k in NaNoWriMo last year, and other milestones of importance to me. What is it about ink that appeals to us so much? Is it the gift of rememberance or something more?