I don't wear the same style of clothes or hair style now as I did years ago. I don't like the same music either. I don't like the same cars. My tastes change. It's not a "maturity" issue either, it's just change.
That said, I personally shudder at the thought of marking my body permanently for a whim I have today. It's just too high a chance that I'll change my feelings about it later and won't be able to undo it. So tatoos have always been out of the question for me.
On other people however... well, it depends on the person and the tatoo. But I don't have to live with it so I don't give it much thought nor care all that much either way.