As far as I can tell, many people get a tattoo because it’s decorative–they like it, it’s pretty/cool/scary. If they have an interest, e.g. cars, they are likely to get a picture of a neat car. So getting a tattoo that is decorative and speaks to your long-held interests is pretty normal.
Until a few years ago, I thought that the only tattoos we could get were the ones on display in tattoo shops. Now all of us are learning that really good tattoos are original art or copies of good images that aren’t on a standard tattoo-shop decal. We’re just not used to people stepping out of the usual skulls, roses, flames, thorns, spouse’s names, etc. Science is awesome and full of fascinating images. Take a look at the science tattoos photo gallery on The Loom.
“Atheism is a religion like 'not collecting stamps' is a hobby.”
―Penn Jillette “If atheism is a religion, then bald is a hair color” ―Mark Schnitzius "If atheism is a religion, then health is a disease!" —Clark Adams