To know that we know what we know, and to know that we do not know what we do not know, that is true knowledge.
知道我们所知道的，知道我们所不知道的，这才是真正的知识。
Around computers it is difficult to find the correct unit of time to measure progress. Some cathedrals took a century to complete. Can you imagine the grandeur and scope of a program that would take as long?
我购物故我在。
To find out what one is fitted to do, and to secure an opportunity to do it, is the key to happiness.