Television and the movies have a tradition of such disabuse. If you have ever watched a movie of a book, not necessarily a classic, you know what I mean. I read Scott Turow's Presumed Innocent before I watched the movie and was sorely disappointed by the casting of the defense attorney, Sandy Stern. In my imagination, he was suave, charming and the consummate foreigner. In the movie, he came across as a hustler.
Television and movies, by relying on a thoroughly visual medium, simply get in the way -- there is very little that you can imagine when it is right there, in two dimensions, in front of you.
A friend to whom I propounded this theory had a ready answer. "Even reality interferes, I suppose," she said, "with your imagination." If I were sane, I would make friends who were too dumb to deflate my hare-brained theories.