Canadian Border

A man lives in a border town between the US and Canada.

He lives on the Canadian side, but works in construction on the US side. Every morning, he walks over to the American side, and every evening, he comes back over to the Canadian side with a wheelbarrow full of sand. And, every day without fail, the Canadian Customs officers check him for any contraband he might try to smuggle in.

For 20 years, the man works nearly every day for the construction company, and every day customs checks the sand in the wheelbarrow, trying to find hidden goods. They sift through the sand, dig in around it, but find nothing. As the years go on, they try to be more clever. They x-ray the wheelbarrow, run tests on the sand, check inside the wheels and axles - whatever they can possibly think of. In desperation, they even strip search the man a few times and run cavity checks. Year after year, they find nothing.

Finally, 20 years later, the man is old and set to retire. On the day of his retirement, he once again pushes a wheelbarrow full of sand across the border. The customs officers stop him and ask point-blank, "Look, we know you've been smuggling something across the border all these years. You have to be. But we've searched through your sand every day for twenty years, and we've found absolutely nothing. It's killing us - please, we'll give you a free pass, wipe away any past crimes, if you just tell us what it is you've been smuggling all these years!"

The old man raised a confused eyebrow and said, "Really? I thought it was obvious, I've been smuggling wheelbarrows."