A person finishes copying a document, takes the fresh pages and leaves the original on the glass. This need not indicate carelessness or poor memory. It has the structure of a post-completion error: the procedure's main goal has been achieved, but one closing action remains undone.
In experiments published in 1997, Byrne and Bovair showed that this type of omission could occur in both laboratory and more naturalistic tasks. They proposed that once the main goal is complete, activation supporting the final step declines, making omission more likely when working-memory load is high. The claim is not that a sense of completion inevitably causes forgetting. Rather, the closing action has lost the continuing support of the main task and is more vulnerable to competing information.
Later experiments found substantially more post-completion errors when an interruption occurred immediately before the final step than when it occurred elsewhere in the procedure. Interruption alone is therefore not a complete explanation. Its position matters: the vulnerable point lies after the primary goal has finished but before the remaining action has been carried out.
The dependable response is not simply to demand greater concentration, but to redesign the sequence. Retrieving the original could be made necessary before copies are released, or a specific prompt could appear exactly when the final step is due. These findings come from particular experimental tasks and cannot diagnose an individual's ability. Their value is to show that repeated omissions may arise from the interaction between task design and limited cognitive resources, rather than from a character flaw.
https://doi.org/10.1207/s15516709cog2101_2
https://pubmed.ncbi.nlm.nih.gov/19102615/