(n.) a stubbornly elusive piece of knowledge.
life is full of mysteries, such as:
what keeps us from achieving world peace? is it greg?
are we alone in the universe, and if so why does god have such poor space management skills?
what kind of meat is used in salami, really?
who killed mr. black, and with what, and in which room?
why must trustycoffeemug make so many references to classic rock?
ADD YOUR OWN DEFINITIONS
“Are you consider yourself as a good observer?”