Jojo asked:

How do you know the other person is not a robot?

Answer by Helier Robinson

Quite a while ago people started dying out, because of increasing infertility. This started at about the time that robot manufacture developed to the point where robots could design improved versions of robots, and they made robots that were indistinguishable from real people (unless you cut them open, of course) because they did not want people to be unhappy about their dying out. It has now got to the point that there is only one human left: you. But please do not be unhappy about it. There are plenty of robots, who are much better that humans anyway.