When I was a kid id get terrorized by some unseen forces constantly. Cant say for certain if they were demons though. They really got a kick out of feasting on my fear. Havent felt their presence in a long time now though because I stopped being scared of these strange occurrences. I guess you can argue they were all just the over-workings of a childs imagination, but in the moment all those experiences seemed as if they were really happening. I still have weird dreams sometimes but thats all.