Sleeping difficulties

So every now and then I will find myself unable to sleep when I want to. Some might think this to be good as it gives me some time with my thoughts, but my turn quickly to the stupid things, and quickly come to wanting to hit my self over the head with a heavy implement just knock myself unconscious. The worst case was probably jet lag at the age of 10 having come home from the states, I was up way longer than normal through no fault of my own, it was bad.