Ahh, that lovely feeling of floating downstream as you slowly drift off to sleep! Arms and legs get heavy and the mind wanders freely through grassy meadows and alongside peaceful streams. If only it were always like that! Or even sometimes. For those suffering from sleep problems the mysteries of sleep can be enough to keep you awake at night but puzzling over them doesn't always help bring the sleep we crave. So what is sleep and what can we do when we can't sleep?