A child points at a plant and asks “Daddy, what is that?” The father replies “It’s a rose.”
Does the child now know what the plant is? No. “rose” is just a word, a sound. It is a label that we humans have invented. That word/sound/label says nothing about the plant. The plant is still very much a mystery to the child (and to the father).
The child asks his father “How do birds know where to fly south in the Autumn?” The father replies “Instinct.”
Again, “instinct” is just a word, a sound, a label. The ability of birds to know where to fly is still very much a mystery.
Much of our knowledge is pseudo-knowledge (fake, false, pretend).
Here’s a slightly different way to put it: Everything is vague to a degree you do not realize till you have tried to make it precise. (Bertrand Russell)