Just wanted to share my experience and get a few people's opinions, as I'm not entirely sure what is going on!
The memory that stands out to me most is also one of the scariest ones for me to remember, and since I was completely awake and it was only a few months ago I can remember it very clearly.
It was late, about midnight, and I was listening to music in bed. I thought I heard someone outside my bedroom door and so took out one earphone to see if I was able to tell who it was by the sound of their footsteps or something. Instead I heard a voice - a young woman, or a young child who sounded old (I don't know what that means either, it's what popped into my head at the time) saying, "Hello? Hello? Is anyone there? Hello?" At which point I freaked out and put my earphone back in. I could somehow tell that the voice was repeating what it was saying, asking if anyone was there. I was terrified - the voice wasn't that of anybody in my family, and it didn't sound like it was coming from a tv and if it was from my sister or parent's room I know for a fact I can't hear it from my room anyway, much less with all the doors closed. Once the song finished I took out the earphones and listened, even though I was terrified, and I couldn't hear anything. I was still scared but knew that I should probably go to sleep.
Lying on my front, not even close to being asleep, something was getting closer to my ear and it was something or someone breathing heavily. I stayed still until it was so near that it was literally in my ear, when I leapt up and pulled the duvet over me, so I was curled up underneath. I heard and 'felt' strange things, like that someone was in the room with me and a humming from the foot of my bed. My night continued like that for a few hours.
The second thing for which I have found no reasonable explanation happened very recently. I was again sitting on my bed, when I saw a yellowish light next to me, which vanished with a sound that was something like, 'meeep', kind of humming I suppose, and the kind of thing you would hear in a sci-fi of someone disappearing into mid-air. It was very loud, right next to me, and had gone within seconds.
I get a lot of deja-vu and I have always been able to 'sense' that things will happen, and have dreams that come true a lot, such as once I had a conversation where I could tell my friends exactly what they were going to say because I had dreamt exactly the same thing around a year earlier. I had remembered the dream because it seemed so realistic.
I've always passed things like this happening as just coincidence; it's only now that I'm beginning to think that it could be something more and remembering exactly how often it happens. I get the feeling that I'm not the only person in a room sometimes, and when there's something that people aren't telling me. I'm 14 and telling my friends that last night I thought there was a spirit wandering round my house doesn't really go down well.
Any advice or explanation would be really great, and thanks for taking the time to read this anyway.