I'm not a kid (see my other replies in this thread lol), but I've never had to use PDFs for much at all. The closest I've ever been to editing one is clicking a box to draw a signature or check a checkbox.
So I've gotta ask. Why would one need to rotate a PDF? They would be made on a computer, and naturally default to the correct orientation, no? I can't imagine why one would ever be sideways.