Today’s Retail strip* reminds me of the first time I ever heard of a Mobius Strip. It was a battered old copy of a ’50’s SF mag which featured a story in which a new highway system designed to bypass a small town had everyone in a state of consternation because cars got onto the road and never came off, just disappeared. Turned out the thing was a classic continuous loop which allowed no exit. I can’t remember how they discovered the answer or solved the issue, but I do remember cutting out a long strip of paper, twisting it appropriately and then drawing a single line with a red pencil which proved  it was all true.

*Sorry, can’t link to it at present; site appears to be down.