There is a stark contrast between our attitudes to sleep and those of the pre-industrial age. In Shakespeare's Julius Caesar we are told to "Enjoy the honey-heavy dew of slumber". There seems little chance of this today, as we crave more, work more and expect more, and, in the process, abandon sleep. Our occupation of the night is having unanticipated costs for both our physical and mental health, which, if continued, might condemn whole sectors of our society to a dismal future.