“Old Millennials, as I’ll call them, who were born around 1988 or earlier (meaning they’re 29 and older today), really have lived substantively different lives than Young Millennials, who were born around 1989 or later, as a result of two epochal events that occurred around the time when members of the older group were mostly young adults and when members of the younger were mostly early adolescents.” Jesse Singal, an Old Millennial, explains.