Do you have trouble getting to sleep at night? Spare a thought for Leslie Gamble. He claims he has not slept for 11 years. On the other hand Joyce Hannon always feels incredibly tired. Many times a day she simply falls asleep whatever she happens to be doing. Joyce has narcolepsy -a quarter of a million Americans have it-but the odds are you won't have heard of it, because the world of sleep is shrouded in ignorance. Yet it's a world in which we spend a third of our lives.