Like most people, I have muscae volitantes ("floaters") in my vitreous humor, and I have been aware of them from a very early age. Noticing floaters is apparently rare enough that there is a medical term for it: myodesopsia; for the non-noticers among my readers, they look like little transparent wormy things that float around in the visual field and are generally invisible unless you deliberately pay attention to them.
When I was very young -- approximately three years old, I think -- I somehow got it into my head that I could catch these little invisible critters and make them less invisible. (I thought of them as something "out there" in the world, but which only I could see, and had no name for them.) I had a very clear image in my head of what equipment I would need to do this:
This is a piece of brown corrugated cardboard, to be cut from a box. The rainbow stripes were to be applied in crayon. As you can see, the whole left half was to be rainbow-striped, while on the right the colors would be applied only to this shape. The mental image of this was extremely clear, like a photographic memory, although I never actually made it. It was an image of what I needed to make.
The most important component, though, was plastic wrap. Stretching a piece of plastic wrap over the crayoned cardboard would cause the floaters to become trapped under the plastic, and the rainbow colors would be transferred to them, so that they would no longer be transparent and nearly invisible but all rainbowy and clearly visible to all. I'm not sure what I was going to do with them once I had caught them -- Keep them trapped? Release them into the wild? -- but I could cross that bridge when I came to it.
First, though, I needed some plastic wrap. I needed that first, because if I colored a piece of cardboard and then asked my mom for some plastic wrap to cover it with, she would obviously not agree. So, before doing anything else, I went and asked her, "Mom, do we have any plastic?"
She asked what kind of plastic, and I said just plastic, and she explained that there were many different kinds, pointing out various objects in the house that were made of plastic. I finally made her understand the kind I wanted, and that is when the term plastic wrap first entered my vocabulary.
Then, of course, she asked what I wanted it for -- and I was at a loss to explain. I mean, communicating the concept of "plastic wrap" had been difficult enough. How was I supposed to explain the things that I wanted to catch and how I intended to catch them? So I said something unconvincing -- something along the lines of "I don't know" -- and failed to score the plastic wrap, and the whole plan fizzled out.