Hey, I totally identify with your changing goals and values, etc.
Your last comment made me want to reply :P
I got 12 tattoos, 1 on each of my fingers, and 1 on each of my wrists (all the way around). I used to think that I would regret them, but now I'm kind of sure I won't. I've had most of them for 8 years. Spiritual Latin words and crown of thorns (Jesus Christ).
I think it depends on what you get - if you get the name of some music artist you're totally into right now, duh, you're probably gonna regret it a couple of years from now (or months). If you get something that really identifies you, it may just withstand the test of time
Tattoos are a really great artistic expression ... just sayin