there has to be a reason for this. I believe the human body works a lot like a car in that there is a cause and effect in everything and its all science.
how is your temperature when sleeping good? I have found that some people sleep better cool and some warm. But temperature has a huge impact.
Food intake before sleeping? light? I have found I sleep better when I shut off all electronics. Have you tried "tuning" yourself and trying environmental change combos.