This is true of my favorite movies. Take Clue, for instance. When it was first released, they had a clever marketing idea: Make multiple endings, but don't show them all at once. If you wanted to see all the endings, you had to see the movie at least 3 times, at different theatres. I didn't get to see the third ending until the VHS release, because we only had two theatres in town!I'm not quite sure why, but certain movies remain fun even though you have already seen them. You already know the jokes. Perhaps because they still evoke a mood?
Over 30 years later, I still love this movie. I loved the board game, and have found a whole section of fanfiction.net where people have written stories about it (some are quite good).