How to give yourself a surprise treat
It would seem to be difficult if not impossible, on the surface. But here is one proven way: when your stock of pitted kalamata olives gets low (only about 1 c remains of the quart you bought) and you buy the next quart from the Whole Foods olive bar, make the top layer various pleasant oddities: the little mozarella balls in olive oil, the pickled peppers, pickled mushrooms, interesting olives that come with pits (oil-cured olives, Castelvetrano, Cerignola, Niçoise, Alfonso, and so on). Then put it in the fridge to sit until the current tub is used up.
By the time you open it, you will have forgotten that top layer of treats, and a very nice surprise it is.