Nigg said it might help me grasp what’s happening if we compare our rising attention problems to our rising obesity rates. Fifty years ago there was very little obesity, but today it is endemic in the western world. This is not because we suddenly became greedy or self-indulgent. He said: “Obesity is not a medical epidemic – it’s a social epidemic. We have bad food, for example, and so people are getting fat.” The way we live changed dramatically – our food supply changed, and we built cities that are hard to walk or cycle around, and those changes in our environment led to changes in our bodies. We gained mass, en masse. Something similar, he said, might be happening with the changes in our attention.