how are the exaggerations of carrying cheese used to a comic effect

J. launches into a long digression about when his friend Tom once asked him to transport some cheese on a train journey. Everyone sitting in J.’s car left because the smell was too strong. When J. delivered the cheese to Tom and his wife, Tom’s wife refused to stay in the house until the cheese was eaten. They could not escape the cheese's stench until they buried it miles away at the seaside. This of course is quite amusing.