Nick Can't Remember This One (Number 11 of The Things Nick is the Keeper Of)

Apparently, Nick cannot remember the eleventh thing that he is the keeper of. This, of course, is a lie; Nick absolutely remembers this eleventh thing, and is feigning ignorance in order to test his audience. Exactly what he is testing them for, and when he intends to reveal whether or not they passed, is unknown. But sometimes, isn't not knowing better than knowing?