“Pep Guardiola’s list of symptoms is long and unsettling. He has trouble sleeping. He can only take light meals in the evening. On some days, he does not eat at all. He finds it difficult to read because his mind keeps wandering. He feels, at times, intensely lonely. Things can get so bad that they begin to take on a physical form: bouts of back pain, breakouts on his skin. They are not isolated to moments like the one in which the Manchester City manager finds himself trapped, when his team are...