I’m entering the courthouse. I beep at the metal detector. The guards tense up, I empty my pockets. Still beeping. I take off my glasses, my pen, my Bluetooth headset. Still beeping. In deep thought, I show the guards my belt buckle and my phone case with magnetic clasps. The guards inspect the belt suspiciously and finally let me through.

In the elevator, while stuffing my belongings back into my pockets, I discover — behind the phone case on my belt — a folding knife of “anti-dinosaur” size, which I’d forgotten to leave at home…