As much as I love The Beatles (all time favorite band), I don't think I would get the Yellow Submarine tattooed on my body as awesome as it is. But hey, it's your body and you can do whatever you want.
You still have time deary...you can dream all you want but tastes change. When I was 15 I wanted barbed wire around my arm and a picture of Brian Molko from the band Placebo on my lower back. Since then I’ve realized that the barbed wire was incredibly trashy as all hell and I not only don’t like Placebo anymore but I found out that Brian was a total douche bag. If you still really want it with all your heart in 5 years then by all means get it even if other people think it is dumb because its about you and not them.
You can do it at 15, too when you have your parents' permission. And, the lyrics part is gonna be mighty painful and I'm pretty sure you'd remove it after, like, 4 years.