“In an experiment of one, Dr. Kessler tested his willpower by buying two gooey chocolate chip cookies that he didn’t plan to eat. At home, he found himself staring at the cookies, and even distracted by memories of the chocolate chunks and doughy peaks as he left the room. He left the house, and the cookies remained uneaten. Feeling triumphant, he stopped for coffee, saw cookies on the counter and gobbled one down.”
