People shouldn't take advantage of things or people, because one day they may not be there anymore.
Event 1: They were treating him like animals. This contributes to the theme because they would treat him so horribly but then he left them. Event 2: They had a "circus" about him. This shown that they would take advantage f his uniqueness to get money.Event 3: They bought a mansion with the money they saved up. They held a circus where people would pay an admission to get in to the the old man. The two wife and husband used this money to buy a house. This is just another example of how they took advantage of the old man.Event 4: He flew away to other houses. The two couple took so much advantage of him they were too bind to see that he was something special. Instead they saw an opportunity to make money. Well now he flew away is no longer in their possession.