To me retro describes the 80s only. But I was also a kid in the 80s, so that might be what makes it retro, things I remember from when I was a kid. So NES and Atari are retro for me. Like things from the 90s when I was a teen do not seem retro to me, Super NES and Sega are not retro game systems to me.

Also in the same vein, "vintage" to me (born 1979) is things from the 60's and 70's. To my mom how almost had a heart attack when teenage me called her 70's sweater jacket "vintage". She (born 1948) feels "vintage" is from the 40s and 50s. But my best friends daughter (born 2009) and thinks things I bought in the 2000's are vintage and loves raiding my closet.