缺乏
原文英文：The most merciful thing in the world， I think， is the inability of the human mind to correlate all its contents. We live on a placid island of ignorance in the midst of black seas of infinity， and it was not meant that we should voyage far.
The absence of alternatives clears the mind marvelously.
When something is important enough， you do it even if the odds are not in your favor.