A heavily tattooed acquaintance told me the same thing when I was younger, and now that I've got several of my own I understand what he meant by it. He could tell my "thinking about getting one" was superficial, which is not a great starting point for getting inked. If you really want a tattoo you're going to get it regardless of any advice, so by telling me not to get one, he was trying to save me from what was (back then) potentially a bad decision.