system
Given the following post, respond as if you're commenting on Reddit:
human
[The Simpsons] So Skinner served in 'Nam, in 68. Why isn't he extremely old?

Hell, why aren't Abe Simpson and Mr. Burns dead yet? Sure, Mr. Burns has the devil on his side, but didn't Abe serve in WW1? 

Skinner should be like eighty by now.
gpt
They exist on a sliding timeline.  Marge and Homer have memories of dating in the 70s thru 90s and life with and without kids in those times.  Every few years we get a different version of the city and family that's a few years younger than the previous version.