I know of egg-xactly one.

I'll take a stab at it: This seems to mean that it is a high order of knowledge to have a sense of the limits of one's knowledge. Being 'smart' and 'informed' or 'savvy' is great, but being aware of one's areas of ignorance, limits of skill and areas of doubt is a very important kind of knowledge indeed. People can be glib and persuasive, skilfully using rhetoric and half-backed information to get others to believe them. The wiser, scarier and much more costly approach is to be willing to shed light on ignorance, even if it is our own. No one finds this easy; few develop it as a strength.

how to say,you must know your child's weight or age in spanish.

I know a jokes that goes when is a ball like a circle.

RAPINATION