I wonder if all people sometimes feel like there's a net curtain between them and the world.
This happened to me earlier when I was in the pub (bear in mind I hadn't had anything to drink at this point) - there I was sitting with my friends, then my concentration slipped for a moment, and when I looked back they were 'removed'. By that I mean that though I could see them, it was like watching a video of them, rather than having them in front of me. I could hear their voices but the different conversations and the background music and the conversation of other pub-goers meant that I couldn't listen to what was going on, no matter how hard I concentrated. Whenever I did speak, I heard my voice too loudly in my mind, and I wasn't even sure if what I said related to the conversation: other times it felt unnatural, like I was saying words just for the sake of saying something.
This often happens when I go to the pub with my friends: this is one of the reasons why I don't often go nowadays, and why I don't stay for too long when I do go. Tonight I decided to stay until closing, but much as I love being with my friends, I was admittedly quite glad when the last bell went.