So, those round-y car windshield sun shade thingies? The theory is you unfurl it, leave, return to car, re-furl it, and drive on your merry, slightly cooler way. But the theory was pulled out of someone's ass, because those things don't re-furl, ever.
Grasp the corners, bring them together, with a slight twisting motion, the packaging advises. It will re-fold automatically, it adds. It's a damned lie. I can twist that thing until I'm blue in the face, but it will merrily unfurl at me every time, without getting even close to a semblance of its perfectly round, factory-furled state. And I will sit in my rapidly heating car, trying to furl the damn thing, and fail. And toss it in the back seat like a rational person would have done from the first. But I wanted to re-furl it, I really really wanted to, thus asserting my dominance over yet another inanimate object. And it won.