A soldier on leave was trying to impress his girl with his learning standards.
"I'm a radio operator in the Air Force. Radio is such a complicated thing. Even now, after two years of intensive training, I must confess that I haven't the slightest idea how the radio works in the whole complex."
"My goodness!" exclaimed the wide-eyed girl. "It's awful easy. You must turn the knobs and it starts talking."