Can you make sense of this?
The blue line shows the ten-year trend in the marriage rate in Mississippi. The orange line represents how much milk we consume in the United States.
Uncanny, huh? Does drinking less milk result in fewer marriages, or do you suppose that fewer marriages lead to drinking less milk?
How about this one — German cars sold in the U.S. (green) versus the prevalence of suicides by car crash (blue)? Clearly, this graph shows that the number of such suicides is somehow correlated to the U.S. sales of Audis and BMWs.
And if Vigen’s drollery doesn’t do it for you, maybe this xkcd joke will: