The squat, harrassed bus-driver smiles ruefully, which changes everything. London bus-drivers, frazzled, underpaid and usually from the least privileged ethnic groups, rarely smile. They get that fragile sense of control that feels so essential to sanity from sailing past crowded bus-stops, swearing at passengers and braking hard so we fall over. Meditators know there is no control - accept it, it won't kill you. Remind self to meditate, and smile.