Noob Opening Question

Hello, I have a question that's probably pretty dumb, but I don't get it. I've been playing Chess for a couple of months now, and I'm just starting to really study openings. Every Opening I read had the moves of white and black listed, 1. e4 e5 2. Nf3 Nf6 and so on. What if I'm going for a Ruy Lopez, and black doesn't play the moves listed in the opening? Am I still playing a Ruy Lopez? Do I continue making the moves in the book? I'm just a little confused, the way some of the book's openings I read seem almost like black has to play e5 in response e4, but in the games I've played that's not always the case. So do I need to adapt to what my opponents doing or stick with my opening plan?

If you're playing an opening and your opponents don't make the book moves, then it is now a different opening. If the moves are not any opening you can find, then you're on your own

Ahh. See and that simple 2 sentence explanation completely cleared that mystery up lol, thank you.