One day Banzan was walking through a market. He overheard a customer say to the butcher, "Give me the best piece of meat you have."
"Everything in my shop is the best," replied the butcher. "You can not find any piece of meat that is not the best."
At these words, Banzan was enlightened.
What does this mean? Sifu Waller will help you here. The butcher maintains that all the meat he sells is his best. This cannot be true because by definition, best requires worst as contrast; a duality. One defines the other.
It is akin to having 'priorities'. You cannot have multiple priorities since the word priority literally means that which comes first. Everything that comes next is therefore of secondary concern?
Similarly, the phrase 'multitasking' is an IT term adopted by mainstream companies to suggest that a person juggle several priorities simultaneously. As the koan indicates, this is impossible.
In IT, multitasking is the illusion of simultaneity, not the practice of it. Now, that is ZEN.