I'm here, but who's to say my here is your here? In my experience, my here is usually not your here, but rather my here is your there and your here is my there. Thus, in my eyes, I am here but not there, because there is not here, but in your eyes, I am there but not here, because here is not there. You are not here, but you are there, due to there not being here, and here not being where you are. Logically, we are all here at the same time, but one is not in the same here as is another.