Mary Poppins and 3D

I think the first time I thought about 3D in a different way was when my mother read Mary Poppins to me. Suddenly, I saw all the space in a room and that it could be turned in different directions.  For instance, when Mr. Wigg floated up to the ceiling and the children joined him, by laughing! Here's a section called "Laughing Gas" where  laughing sends her up from the floor: "Michael, to his astonishment, saw her go soaring up through the room. With a little bump, her head touched the ceiling and then she went bouncing along it till she reached Mr. Wigg."[1934, by P.L. Travers, illustrated by  Mary Shepard, 35.]