No, not that kind of memory challenge, this kind. The challenge is to provide a written example of a repressed memory from before 1800. The authors have an interesting theory that the concept of repressed memories originated as a 19th century Romantic notion.
Whatever their origin, they were popularized in the psuedoscientific psychonalytic theories of Sigmund Freud, and have done much harm in the 20th century in the form of false memories implanted by therapists.
Update day 2020!
7 hours ago