I realize this is all opinion, however in mine, you are a kid of whatever decade you spent the majority of your childhood in (0-17). So a true 90s kid would be someone born from the years '81-'89. 1980 and 1990 kids are cusp kids; they were born in the 90s just like the real 00s kids, yet lived every year of the decade, so they're on the fence. So the ideal year to be a 90s kid would be someone born in 1981 or perhaps '82; you turned 8 around the start of the 90s, and started your senior year in high school/graduated high school in the 90s. You watched all of the early 90s cartoon shows and sitcoms air live episodes (DuckTales, Pirates of Dark Water, original TMNT, Fresh Prince, C.O.P.S.) and saw Jordan play live, can remember the arcades and video games released from the early 90s and forward. YOU FULLY LIVED THIS DECADE!
THESE ARE TRUE 90s KIDS. So if you were born after 1989 (again, I consider 1990 to be a hybrid), YOU'RE NOT A 90s kid, fukk off