There is no true definition. The word is only used by the master of masters. Although the word phrase has lots its translation and true meaning during the time of the medieval ages, some believe that it means to know "what is best". If someone were to make a wise choice, then another party would exclaim that this person "knew his/her goods" in that specific area.

when you've done something so cringe you can't stop replaying it in your head and it stops you from getting on with your every day life