My boss told me to stop acting like a know-it-all.

This joke perfectly captures the ironic struggle of dealing with a "know-it-all." The humor mechanism here is a delightful blend of dramatic irony and situational humor. The boss, in an attempt to curb the employee's annoying habit, inadvertently sets up the perfect opportunity for the employee to demonstrate that very trait. The punchline isn't just a response; it's a performance, proving the boss's point in the most self-aware, yet utterly oblivious, way possible.

The "know-it-all" is a timeless character found in every office and social circle. They're the person who always has an unsolicited opinion, a correction to offer, or a fact to interject, often believing their superior knowledge is helpful rather than irritating. This joke taps into the universal experience of encountering such a person and the relatable frustration that can arise. It highlights how deeply ingrained this behavior can be, to the point where even direct feedback becomes another platform for demonstrating their perceived intellectual superiority.