By modern standards this is pretty bad, and it boils down to an exposition problem.
The author needs to explain certain basic information up front (or at least pretty early on). A good way to do this is to have one character be a novice who needs to be told basic details, thereby informing the audience. In fact the “new guy” angle to exposition delivery is so good that it itself is becoming cliche.
In the example you brought up the author wanted to take advantage of the “new guy” trope but for whatever could not do that. Maybe the character needed social status or standing that a rookie would not have in order to make the plot work. Rather than find a creative workaround that made sense in their story they pulled out the old amnesia trick to eat their cake and have it, too.
By modern standards this is pretty bad, and it boils down to an exposition problem.
The author needs to explain certain basic information up front (or at least pretty early on). A good way to do this is to have one character be a novice who needs to be told basic details, thereby informing the audience. In fact the “new guy” angle to exposition delivery is so good that it itself is becoming cliche.
In the example you brought up the author wanted to take advantage of the “new guy” trope but for whatever could not do that. Maybe the character needed social status or standing that a rookie would not have in order to make the plot work. Rather than find a creative workaround that made sense in their story they pulled out the old amnesia trick to eat their cake and have it, too.