I arrive home just after noon, from a 21.1-mile run. The effort leaves me gasping for air on the bathroom floor and clutching a carton of apple juice, which I grab from the fridge just before making it up the stairs. The bathroom window is open; maybe the other lodger or the landlord has just had a shower. The mirror is still misted-up. A cool breeze sneaks in. I stretch my tired limbs…