While on holiday in Halkidiki, Greece, a brief thunderstorm broke in the middle of a very hot day when everybody lounging around the hotel pool quickly rushed inside. The scene and mood changed rapidly from balmy, hot Mediterranean sunshine, to rain and dull skies reflected in the still blue pool, with poolside trappings and palm trees forming shapes dappled with gentle raindrops.It made me think about how quickly and unexpectedly a change in weather can change our environment and our behaviour.