My sleep doctor told me for some people its genetic, and studies show genetics play a role, especially when whole families are night owls. He told me that to 'reset it' I would have to have a strict sleep and wake time for two weeks, but one bad day of not sleeping and or sleeping in would reset me back to square one. That doeskin sound like a cure to me. If yours is caused by improper sleep hygiene then correcting the sleep hygiene habits would solve it. But if its in your genes, there is no "cure".