Unintentional humor
This is one of my favorite films, and when I see it I am reminded of something that happened in the 1980s. While in college, I attended an outdoor screening of this film in the campus Grove. Everybody had a great time and seemed to enjoy the movie. However, there was a roar of laughter during the cave scene when Miles realized Becky had "turned" and said:
"I didn't know the real meaning of fear until... until I had kissed Becky."
I still chuckle every time I see that scene.