I never walked out of a movie when I was a dub. My teenage dub friends and I watched R movies too. We were such naughty little dubbies.
My dub mom, on the other hand, almost never watches movies. But my sister (an exdub and just a little bit malicious) recently gave her the DVD, "Pirates of the Caribbean." My mother watched it and told me she was never so frightened in her life. I laughed and told her to never, but never, watch "Jaws," "Alien(s)," or "The Exorcist." I think they would scare her to death.