When filming the scene near the beginning when Macaulay Culkin is asking
John Candy all the questions at the breakfast table, he couldn't remember them and he said it was too fast for him to remember. John Candy wrote the whole script for the scene out and put it on top of his head for Mac to look up at so they could keep up the quick pace of the questioning. (You know, the questions that end with "you ask lots of questions" then "I'm a kid, that's my job")