The people who can still recite a dozen phone numbers from memory aren’t cognitively superior. This is what psychologists call cognitive offloading, and it has been discussed for a very long time. The everyday memory that the world stopped requiring wasn’t replaced by a new everyday memory of comparable weight. The pre-2007 bundle happened to include: holding numbers, holding routes, holding small facts about people, and holding a rough internal check on whether the world matched your model of it. The generation that memorised phone numbers isn’t sharper.