Watchcat Sylvia used to hide in a hard-to-reach spot under a desk. Initially, I could lure her out by throwing a toy mouse to her. As time went on, however, she wouldn't emerge until I threw two toy mice to her. Then, it became four mice, and...the price kept going up. Eventually, when I threw just one or two toy mice her way, she'd peer out and then dart back under the desk to convey, "Nope. Not enough mice."
I was relieved when Sylvia finally stopped hiding under the desk. If our routine had progressed any further, I might have had to throw 28 toy mice her way, in four alternating rows of seven gray mice and seven white mice. Even if I had done that, Sylvia might still have peered out and retreated quickly, meowing as if to say, "Sorry, but those rows aren't quite symmetrical enough."
I guess we all have our standards.