The opposite of knowledge is the illusion of knowledge. The opposite of you know something is you thought you know something, not you don't know something.
I recently realized this random thought when I was coding. When solving software development problems, I usually got stuck the longest due to not the things I didn't know but the things I thought I knew (but I don't). Things I don't know that I don't know are usually the biggest blockers in my debugging process.
Similarly, I think most of the huge irreversible mistakes are not caused by not knowing something but caused by the illusion of understanding. We are more cautious when we are aware of what we don't know. Knowing the boundaries of what we don't know caps the downside.
This also reminds me of The Opposite of Happiness and Love.