Do tattoos have to have a theme?

So I only have three tattoos but they're all very different. I didn't really think about whether I should stick to one style or not when I got my first tattoo. I have a traditional SAP on my upper left arm, a cute elephant with music notes on my lower right arm & a direwolf on the back of my right arm. I've been thinking about what tattoo I want next but I keep holding back because i don't want to look like a sticker book lol..anyway, I was just wondering what other people think of this? Do your tattoos have a theme/distinctive style?