Does anybody else find that they can be yawning and feel really naturally tired around 8-9pm in the evening but when it comes to going to bed at 10pm+, the moment their head hits the pillow, they become stimulated or uptight? This is what happens for me, it then takes an hour or so to calm down my body which has gone into some kind of panic and eventually fall asleep. I quite often attribute this sensation to past insomnia and maybe some kind of ingrained worry about not sleeping, but generally I feel very relaxed at the moment so there is no reason for this to happen. This leads me to thinking that it is something more to do with Cardiovascular, or the digestive system. I do try to sleep both upright with pillows or completely flat but it seems to happen either way, and it is of course much worse if I have exerted myself. It's as if the more activity we do in the day, the CNS becomes more fired up and harder to switch off. Any thoughts?