At any time of a 24 hour period, some part of the world is asleep, for the most part. The preference to sleep when desired is a powerful one. The reasons for wanting sleep are varied.
It could be a result of boredom, or fatigue. No matter the reason, we all attempt to sleep at some time. That is the problem. Is this a major issue - yes. Not being able to sleep when sleep is necessary can result fatigue, illness and injury. Investigating reasons for failing to sleep has become a major point of study. Hopefully, more solutions will be available in the near future.
Sleep studies performed by qualified facilities are currently researching to answer these issues. With their help, much has been learned. This may be little consolation for those suffering, but something is being done. For more information research can start with this link; www.webmd.com/sleep-disorders/sleep-studies. This is just a place to start - final solutions may vary with the individual.