I suppose that every time there is difficulty. I remember about Space Mountain: It took us ten years before we found the technology that would allow such a ride. And during these ten years, I had a model that I kept, waiting for the technology we needed.
Walt had a marvelous intuition. And because he understood people very well, liked them and had great respect for people, there was nothing cynical about Walt.
In live action movies, you just hope that everything works. Because the actor may had a bad morning and doesn't play good, or accidents happen continuously. Many things contradict what you are trying to say. But in cartoons, nothing contradict what you want to say.
Walt put everything he knew about communication with images into the park, so it was very familiar.