Are there other people, according to Buddhism?

When I was on a Self Inquiry retreat last year, I was explaining why I wanted to help other people. One of the two teachers looked at me and said, "**There are no other people.**" That sort-of made sense to me. The next day I had a realization which made it make sense completely. But the other day (is there another day?) I saw it in a different way: that it simply does not matter whether there are other people or not, because I can never have real insight in to them, so I am completely alone in my path. My image of two people is like spheres touching at one hypothetical point (Indra's Net). I cannot see much through a point-sized window on to (hypothetical) someone-else's world. This is like **Vivekacudemani #515**: > *I am Actionless. I am Changeless. I am Partless. I am Without Purpose. I am Eternal. I do not require any prop. > **I am One, without a Second**.* If I am One, can I know anyone else? What does Buddhism say on this point?