I got rid of all mine after getting disillusioned with every one of the causes they represented.
This is the main reason I've never gotten a tattoo - how I feel about whatever it is will almost certainly change.
As a result, I am that guy that tells people a few rules about tattoos:
1. Don't get a tattoo of a band. They will eventually fall out of favor or do something stupid.
2. Don't get a tattoo of any person unless they've been dead for a long, long time. Like a band, a person will also eventually fall out of favor or do something stupid. Even after they're dead, it may still be uncovered that they did something stupid in secret.
3. Don't make your self-expression about other people. Rules 1 and 2 should have already put you on this path.
4. Consider time. So you like cars, especially the 1987 Pontiac Firebird you had in high school. Have you always liked cars? Will you always like cars? Have you and will you always like that car? If there is doubt, rule it out.
5. Are you drunk or high? Best sleep on it.
6. Can you be honest with yourself? This is the Catch 22 question, but an important one. We tend to have a few versions of ourselves to contend with; the one we want to be, the one others perceive us as, and the one we need to be. Sometimes they align, sometimes they don't, but self-expression hinges on understanding the difference and allowing that we might be deceiving ourselves about who we really are, sometimes.
Getting a tattoo is a remarkably difficult and personal thing that I see a lot of people not take seriously enough, then live to regret it, myself included. The artist who has now done all my visible work is an absolute master at getting people to slow down and think about what they want, which was a terrific boon in my life, because he probably did more for me as a person than my therapist did. His clients are life-long, one even having traveled from another country to get more work done by him. That's to say nothing of his absolutely radical art and style that always produces something unique and fit for the person to make part of their lives.
It's something I often think about when I look down at my arms, see those old game homages and realize, regardless of what else has happened in my life or whoever I thought I was at the time, they have been with me since the beginning and are still here, helping me through it.