Honestly, I was a plastic sheet guy for years. Always had those same wet patches and those weird soft lines where the sheets overlapped. Tried the spray on a shed floor last month and it was a total game changer. The color stayed even, no blotches at all, and it just felt like a harder surface when it was done. I'm not going back.

Check them in good light, you can usually see it.

That "line" idea is okay, but it misses the key part about doing something a set number of times. A real for loop is more like telling one person to take three steps, not telling three people to each take one step.

See it with everything from kitchen knives to car brakes.

Just one bolt" is exactly what @claire_fisher41 means about theory versus reality.