I think/believe we can sometimes get to know/experience this in lucid dreaming. I think of identical twins that may swap positions for a little while to experience what it is like to have the life of the 'other'.
I sometimes wonder that if I am temporarily occupying the space of an alternate "David" in a parallel universe, then where is the "David" from that universe? Is he occupying my space simultaneously? Hope this makes some sort of sense, crazy though it sounds.