<human>: So just like 5 minutes ago I was lying down in my bed and I don't exactly know what I was doing, but I was tired from my day so I started to sleep. I felt like I was dreaming (not lucid or anything just normal) but nothing played out in my head, however I could hear a voice which I could tell wasn't a human voice because it was in my head, I just know. And so I wanted to get up but I couldn't. I wanted to go out of my bed but I couldn't and I still felt like I was kinda dreaming but I also felt like I could see my room from my perspective, I fell back into a deeper state of sleep, not to dream but it felt stronger, and then I tried to get up again and I couldn't this time I felt like my legs wouldn't move. I was able to move once someone knocked on my door, but why does this happen?

Give me the gist of the text in a nutshell
<bot>: I fell in and out of a weak dream where I only heard a small voice and couldn't get up out of my bed but I wanted to, WHY?