I love this show, but it has the worst consistency, which really bothers me. This show does not exist on any sort of timeline. I've read about a theory that this world takes place in an alternate universe. This is definitely true, as while this show is based on real life events, it is not nonfiction. This universe is very similar to our universe, but the events of the 80s occured in a completely different order, also Adam Goldberg has a sister instead of a brother, etc... I'm going to consider this all a fact, since it is the only thing that makes sense. Every season of the show is acknowleged to be an actual year in the characters' lives meaning so far we've seen 5 years of the Goldbergs at some point between 1980 and 1989. Episodes don't necessarilly take place in the order they air. Every episode is based on the real Adam's specific memories that take place at an unspecified time in the 80s. This covers up a lot of inconsistencies, but there are still some issues.
Characters age at different rates:
Adam is 1 year older every season and keeps moving up a grade (ignoring the fact that he says he's in seventh grade in season 1 when he should be in sixth.
Barry is 16 when the show starts, making him 5 years older than Adam. He must have been at least a sophmore, unless he repeated a grade, which is very possible knowing Barry. 4 years later, Barry is a senior and Adam is a sophmore. Now he's only 2 years older than Adam? Barry should now be 20 and should not be in high school. There is no indication that he repeated a grade during the run of the show and he has the same classmates every year.
Erica is older than Barry, making her around 17 at the start of the show. There is no way Erica would get held back. Somehow she doesn't graduate until the end of season 4, when she should already be 21 and has gone through 4 years of high school during the run of the show. We also see flashbacks to her freshman year, which occured before the start of the show. Erica always seems to be 1 year older and 1 years ahead of Barry, but her age difference from Adam changes from 6 years to 3 years.
I have no explanation for the above. I could look at specific episodes and see what indications they give of the characters' ages and where it takes place in the overall timeline. There doesn't seem to be one timeline that this entire show can be placed on. I know in some shows every episode is independent of each other, but on this show there are plotlines that continue for multiple episodes and even seasons.
Beverly says she dropped out of college her freshman year because she was pregnant with Erica. She met Murray when they were both in college and supposedly around the same age. Murray turns 50 when Erica is a senior, making him roughly 32 years older than her. Did Beverly and Murray both not attend college until their late 20s? Why?