How did the three friends create a mess while packing their things

In Chapter Four, J. volunteers to pack the clothes, believing himself an exceptionally efficient packer. However, he keeps forgetting items, and then has to unpack in order to fit them in. To the reader, he expounds briefly on his habit of losing his toothbrush when traveling.

Harris and George watch J. pack with great amusement, and volunteer to pack the food when J. finally finishes. They are no better at it – they constantly forget items, and Harris steps in the butter. Throughout it all, they keep tripping overMontmorency. After some bickering, they finish, and assign George to wake them up at 6:30 the next morning.