Careful studies have not found any convincing cases of that could not be explained by other factors, such as disease, brain injury, normal forgetting, or an unwillingness to think about disturbing events.

Careful studies have not found any convincing cases of "dissociative amnesia" that could not be explained by other factors

Dissociative amnesia is one of a gathering of conditions called dissociative disorders. Dissociative disorders are psychological sicknesses that include interruptions or breakdowns of memory, cognizance, mindfulness, character, and additionally discernment. When at least one of these capacities is disturbed, side effects can result. These manifestations can meddle with a man's general working, including social and work exercises, and connections.  

a factory opens that mass-produces light bulbs.

explanation:

not sure if that's an answer to your questions but this is an example! : )