Shannen, Jennie, Tiffani, and at first Brian looked and seemed credible as high schoolers, but the various others either not so much or (in Luke's and Gabrielle's cases) not at all. Still, I was a fan.

I always thought this series' high school-age "kids" were unrealistically much too wordly, regardless of them supposedly having come from Hollywood privilege.

During the last couple or so decades, I've had cause to go (one time apiece) into two area former malls that, back in their heyday of the '70s, '80s, and to lesser extent the '90s, when during those decades I visited each many times and they seemed vast and spacious, in more recent times, converted over into offices space, or an archiving facility, and in one of the former mall's case partially used as an indoor walking track, they seemed decidedly dinky.

Benton, odds strike me as likely that our ages are within ten years of one another; I've long suspected you may have been born 5-10 years before me.

Shannon was like 19 at the time but she too was a legal adult from the beginning and soon was in her 20s playing high school. About our ages-- maybe.

This series ran from 1990 to 2000. As all or most of the main players were already young adults (I suspect ages 19 to 25 or thereabouts, most of them) when the show began - at which time they were supposedly 10th graders* - they for sure aged-out early on as credible teenagers, and some of them even as supposedly in early or mid 20s.

Btw (to save anyone from feeling it necessary to correctly inform that some of what I last stated technically isn't exactly accurate), allow me to quote from this series' Wikipedia article:

In the first season, the teenage characters (aside from David Silver and Scott Scanlon) were said to be in the eleventh grade, but due to the success of the show, *their ages were retconned to be one year younger in the second season, making them tenth graders in the first.

@Benton12 said:

Even when this began. I think every last one of them was higher than 18 years of age. Gabrielle Carteris was especially hard to accept in this. It destroyed the identification real life teenagers would have watching these actually then 20 somethings.

It's quite common to have actors older than 18 years portray teenagers in films and television, because of e.g. labour laws, 'risky, mature' themes, extra costs for tutors, chaperones, intimacy coordinator, etc..

For example in " Pretty Little Liars (2010-2017)" the main actors, who played 15-16 years old teenagers, were all older than 20 years, with Bianca Lawson being the oldest. She was 31 years old, when she played 16-year-old Maya St. Germain.

Good quote,Gen. Remember or realize: Melody Patterson was a high school age teenager when she first did F-Troop!