Why do we tattoo our skin? It doesn't make logical sense. We pay someone to poke us with needles. We inflict pain on ourselves and damage our skin.
Because we want to etch life on our skin. We want to carry memories with us.
The tattooing process is a snapshot of all things in life worth anything. We have an idea for something inspiring or beautiful. Then we go through tons of pain and work to bring it to life. And in the end, we have something we can celebrate and look back on.
(Or maybe there is no analogy between tattoos and anything else in life. This could all be useless ramblings. Either way, do yourself a favor and listen to this song.)