An adventure at the supermarket 17

A supermarket is just a place to shop, where no one expects anything special to happen. That day, however, the customers seemed to be out of their minds.
Why did a big man dressed in white so desperately want the toothpaste João had in his way? And why on earth would an old man be catching flies to put them in margarine packets?
Everything seemed even more absurd when João returned home, squeezed the toothpaste into the sink, and instead of hearing a plop, he heard a plink.