What does the number of people who drowned in pools have to do with the number of films featuring Nicholas Cage?
Or World-Wide non commercial Space Launches have to do with the number of sociological doctorates awarded in the United States?
Check out the website Spurious Correlations for simple graphs that highlight how easy it is to confuse a correlative relationship with a causative one. The site is managed and maintained by Tyler Vigen, a law student at Harvard. An excellent visual resource for teachers of statistics, economics, social studies, civics, science, and more.