Okay, the oddest thing just happened to me. I was sitting upstairs in my kitchen working on my laptop, when suddenly my brother randomly stomped halfway up the stairs, said "What are you doing?" and walked back down. There was a wall between me and said stairs, so I couldn't see him and he couldn't see me. Of the 4 people that where in the house, one was sleeping, two where in the kitchen, and he was on the stairs, so there was no one that was in his line of sight. When he came back up later he didn't recall it, and thought I was crazy. There where two witnesses, me included, who say it happened, so I know I didn't just imagine it.

Also sometimes when he is alone we hear him whispering random things to himself, which he claims never happens.

What is going on?

I personally think he may be falling into a day dream and randomly sleep walking. Any thoughts?