““The slab of stone is the problem we’re facing. The tank of water is our potential for changing that problem. And the drop of water is what we’re actually able to do, at any given time.” I can’t help it—I laugh. “Not very encouraging, is it?” She smiles. “That’s one way of looking at it. I prefer to look at it another way—which is that if they are persistent enough, even tiny drops of water, over time, can change the rock forever. And it will never change back.””