"Just a Minute" is a British quiz show which half of the contestants didn't know how to play either. Nevertheless, they all gamely and competitively rose to the challenge of discussing topics such as "Brides of Dracula" and "Garden gnomes" without hesitation, repetition, or digression for one minute - while aggressively stealing parts of that minute back and forth from each other. Truthfulness was optional.
SF/F convention masquerades are not big balls where everyone wears costumes (much as that would be fun). They're costume competitions, done up on stage, with the audience watching.