There's a reason people that own one cat go crazy and have brain damage and end up owning more of those things.
The Toxoplasma Gondii requires cats to multiply, so it alters the behavior of its host rodents in order to steer them towards a cat's digestive system.
Now, humans and cats have lived together for millenia; it makes perfect sense that the Toxoplasma Gondii might also have steered us into giving their furry brothels a comfortable place in our homes and our beds... And for the cats, they have two species directly feeding them: Mice and Men. Perfect case of symbiotic evolution.
You'll never see Lassie do anything that smart.
Now, back to the parent post about working at PetSmart:
I've seen coworkers that were normal before become irritable and irrational after getting a cat.
Are you sure that's not just caused by working retail for long enough?
And then there was me, working at Home Depot, wearing the trademark Orange Apron. We had a cat in the store; it ate the mice that lived on the birdseed in the Seasonal Department. As I walked into the lunchroom, about 30 people eating lunch, big shift change time of day...
"Hey Lawrence! I hear you found the store cat!"
"Well, I found part of the store cat..."