Maybe they're all TSB customers?
I suspect it's a combination of factors. Everyone's tired and fed up after the seemingly endless winter and the disappointment of last week's 2-day summer. Generally, this just isn't a happy country: so many political uncertainties; endless news of bureaucratic incompetence, cover ups and corruption; economic doubts leading to worry about jobs, money and homes; health worries; ever increasing utility bills and annoyance over every day irritations such as littering, potholes in the roads and broken pavements.
I woke up feeling fine this morning but just thinking about that lot is making me tired and cross! Maybe we'll all feel better and smile more if we have another few days of sunshine and, for sporting enthusiasts, if England win the world cup and a Brit wins the Tour de France?