The Smart Smuggler

When John came up to the border on a Motorcycle, laden with two large bags, the Customs officer asked him, "What's in the bags?" John answered, "Sand." The officer said, "Very well. We'll see about that.” The officer then took the bags, ripped them apart in a furry, and emptied them out and found nothing in them, but sand. He detained John overnight, had the sand analyzed, only to discover that there was nothing but pure sand in the bags. The officer released John, put the sand into new bags, lifted them onto John’s motorcycle, and lets him cross the border.

Five days later, the same thing happened. The officer again asked, "What have you got in the bags?" And John again answered,  "Sand." The officer did his usual thorough examination and discovered that the bags contained nothing but sand. He gave the sand back to John, and John crossed the border on his motorcycle.

After this sequence of events had continued for over two years, John stopped showing up. Then one day, the officer met up with him in a nightclub in the city. "Hello my friend," the officer said amiably. "I know you were smuggling something, but not being able to figure out what it is, has been driving me crazy. It's all I think about. I can't even sleep. Just between you and I, what were you smuggling?" John smiled, and said, “Motorcycles.”