I saw a video on how caffeine works by chance... ...and then I googled Adenosine. https://www.howsleepworks.com/how_homeostasis.html Check out the diagram on that page. Think about how your diagram would look. So, if all this research on sleep exists, is there much about how it manifests with people with ME/CFS? Maybe I have an unnecessary build up of Adenosine, or maybe there's something wrong in my sleep that doesn't make it clear out. I feel like I have grogginess for hours after I wake up, rather than half an hour. Why does that happen? Is there research going on about this? Or is sleep research not relevant to ME/CFS?