In the early 1980's…
We had a VAX-11/750 (IIRC) with multiple dumb terminals (24x80) hung off of it.
I noticed that most programmers did not logout before going home at the end of the day.
I noticed that our secretary used to arrive to work before all of the programmers arrived.
I asked the secretary to perform backups every morning before the other programmers arrived.
I wrote out instructions in the form:
About a week later, I came in early, after the secretary had arrived, but before all of the other programmers had arrived.
on every terminal.
I asked the secretary what happened. I got 2 answers:
I had assumed that my instructions were sequential.
The secretary started reading the instructions from the top after every operation.
The single sheet of instructions was a parallel set of instructions in the secretary's mind, but serial in my mind.