Memory serves critical functions in everyday life, but it is also vulnerable to error and illusion. Two decades ago, I proposed that memory errors could be classified into seven basic categories or "sins": transience, absent-mindedness, blocking, misattribution, suggestibility, bias, and persistence. I argued that each of the seven sins provides important insights concerning the fundamentally constructive nature of human memory, while at the same time reflecting its adaptive features. In this article I briefly summarise some key developments during the past two decades that have increased our understanding of the nature, consequences, and adaptive functions of the memory sins.