At my first job in commercial radio, at WWST Radio on Wooster, Ohio, right after my high school graduation, the station's engineer pranked me.
He ran into the control room and shouted, "We're off the air! Make an announcement! Hurry!"
I opened the microphone and said, "Ladies and Gentlemen, WWST Radio in Wooster, Ohio is off..."
That's when it dawned on me. If we were off the air, no one would hear my announcement. If we were not off the air, my listeners would think I was nuts.
I went on to be on the radio for 34 years in dozens of stations.