Am I really out there?

Is reality relative?
And if so, relative to what?
I was at work today and got into one of them conversations when you're not quite sure you are both talking about the same thing, but you get to a point in the conversation when its too late to ask without appearing to be rude.
Well, at that point I just kind of mentally switched off and started to think about whether this was happening to me in another plane of reality and if so was I having the same success as here.
It got me thinking, if alternate universes exist, then they must be linked somehow to ours. If thats the case then all the alternate essences that are me could be linked. It could be for instance that when I'm dreaming I'm actually seeing visions of other realities which don't always make sense. That could be why I sometimes wake up wondering about the strange dreams I have, they are too vivid and realistic to be made up but too strange to have actually happened to me. Sometimes I really need to sit on the end of the bed and concentrate to decide whether these were dreams or they actually happened to me.

No wonder I have headaches some mornings!