A childhood belief about under my bed

when i was a kid (5-9 or so) i thought that there was a monster that wanted to eat me. it could be under my bed or in my closet or even come in the window if it was open but it could only come out in the dark or when nobody else was there. it was important not to let any part of my body jut out over the edge of the bed or the monster could pull me out. similarly I would always take a flying leap onto the bed so it couldnt grab my ankles and pull me under. When it was dark, keeping the covers pulled up over my head meant the monster couldnt touch me although it might be right there. If i didnt see it, it couldnt eat me. I didnt know what it was or how it looked because i thought if i ever saw it, I would go mad. It was big though. at five or six I would sleep facing the wall and put my teddybear back to back behind me to protect me. later on, i dispensed with the teddybear, but when i felt the hairs on the back of my neck stand up i would still sleep with the covers all the way over my head, even though i knew there was no such thing as monsters.