For me, since I had this trouble, I decided to follow this rule: "Don't sleep until your eyes by their own shut dawn" :D. In this way, I sleep like children !

(stanca di addormentarmi tardi, "sleeping late" potrebbe significare "andare a letto, go to sleep") [...] I remained (stayed) in my bed [...] You may be simply too tired, stressed in order to fall asleep. The reasons may be different. Among those there can be changing of daily activities (too much or any physical activity at all, as well as mind activity -too many thoughts, or any :D-), too late, or too rich or badly balanced, meals, too much pc -that is watching luminous screens in general from a little distance-, too high temperature in the room and other ones. Of course going too bed asking him/herself "Will I succeed to sleep enough this night?" cannot help very much to get relaxed so one should take it easy as much as possible. :-)

It happens often to me, this is the story of my life, insomnia. I do nothing when it happens, sometimes I leave my bed to read, to drink milk.. and I avoid getting angry.