I get what you are saying that it is more succinct. However the next statement "it is not true to say ..." confuses me. In fact there are many cases where I did

I get what you are saying that it is more succinct. However the next statement "it is not true to say ..." confuses me. In fact there are many cases where I did not know that I did not know something important. I was cross country skiing across a frozen lake. The ice was 24 inches thick. I knew it was that thick. I did not know that where a lake narrows there can be current that prevents ice from forming. Moreover, I was unaware that there were major issues about frozen lakes that I was unaware of. I was not aware there was any risk and therefore came much to close to falling through the ice. Those little "crack crack crack" sounds stick with me. There have been other examples when I was unaware that I was ignorant of life threatening issues. My use of that phrase is perhaps particular to the fact that most of my realization of "unknown unknowns" has been when they are life threatening.