A lot of people are too young to have ever experienced what it was like to use unix systems with lots of concurrent users "back in the day". Back then there we

A lot of people are too young to have ever experienced what it was like to use unix systems with lots of concurrent users "back in the day". Back then there were a lot of different ways to communicate with other folks on the same system, although many of them have modern analogues. "talk" was a primitive IM system that could be used to communicate between two people logged into shell (tty) accounts on a unix system. When initiating a talk connection it would pop up a prompt on the other user's terminal, which is why it's mentioned as being an interruption. It would interrupt someone else's workflow quite abruptly. "write" was even more primitive, it was a way to directly send text to someone else's terminal. Back then the community of users was small, not truly anonymous, and there were strong external authorities that helped prevent abuses (most net users were students or academics, abusing systems could get you kicked out of school or fired). As the internet became more widespread a lot of these features were locked down and turned off on most systems.