Yes, you can communicate with others, but that's external communication, distinct from the kind of communication your internal feedback loop provides to itself. You don't experience them as a "self" because they don't have access to the internal communication methods between your specific cells and brain structures that those systems interpret as "self". They feel "different" because they do not provide the same input into your system as your own consciousness does.
Perhaps if there were a way to link 2 people at a neural level, to where their neurons were receiving input from each other, we WOULD see a break down of the walls of self.
Actually, just wait a few years until
these two girls' language skills improve (they're reportedly a little bit slow on the developmental milestone scale, but progressing steadily). They might be able to provide do a better job of explaining than me.