In addition to being funny, it gives me the occasion to mention research which indicates that having cats can make you crazy. This story describes Toxoplasma gondii-- a parasite that can migrate into one's brain and change behavior!
As such, it joins a short but interesting list where cause and effect are difficult to ascertain-- examples of false-cause fallacy, something covered in the first chapter of every Econ book.
Other examples: We used to think that elderly people fell and then broke their hips. Now, they think that they often break their hips while standing-- and then fall. Or a policy example: if guns purchased and crimes increase in a given year, are people buying guns to commit crimes-- or are they buying more guns (to defend themselves) because more crimes are being committed? Without better data, the inferences from the data will be driven by one's priors/biases.