Wish Battery

So, I was talking to Siobhan about how her twin sister stole her birthday wish since they shared a cake, and thought what if we can just store up wish power to use later? So like, I could throw a fistful of change in a fountain, but not make a wish, just store up my potential. Or see shooting stars, or blow eyelashes and all those things, but just sort of mentally shunt it into your wishing bank account. And that the older you get, the more room you have for wishing power. You have as many slots as you have candles on the cake. So before my next b-day wish I'm gonna have to see a lot of falling rocks...