The Big Bang Theory’s finale rejected the show’s entire premise by showing how much its main characters had transformed over the years. In its twelve seasons, The Big Bang Theory chronicles the day-to-day lives of geeky, socially inept scientists Sheldon Cooper (Jim Parsons), Leonard Hofstadter (Johnny Galecki), Howard Wolowitz (Simon Helberg), and Rajesh Koothrappali (Kunal Nayyar). Along with Nebraska native Penny (Kaley Cuoco), they explore the intricacies of adult life, pursuing various careers, entering relationships, and learning more about themselves. By the end of The Big Bang Theory, these characters have become drastically different from who they were years before, effectively dismissing the show’s premise in the process.

Since most of The Big Bang Theory’s characters are scientists, a significant part of their journey within the show revolves around their respective fields. Additionally, the primary male characters are stereotypically categorized as avid followers of science fiction, comic books, and fantasy literature. Meanwhile, with her street smarts and high school education, Penny is considered the direct opposite of her nerd friends. The contrast between their personalities often provides humor and conflict in the sitcom juggernaut.

RELATED: Why The Big Bang Theory Doesn’t Reference Sheldon’s Children

Anchored on the abovementioned descriptions, The Big Bang Theory’s premise focuses on its main characters being losers in one way or another. Despite being highly educated, Sheldon and his group of friends are terrible at social interactions. An early implication is because they have difficulty meeting new people and maintaining relationships, they will spend the rest of their lives shunned from the world. On the other hand, Penny’s lack of education and marketable skills cause her struggles, especially with her career prospects. However, as seen in The Big Bang Theory’s final episode, all of them have turned their lives around, experiencing and reveling in their personal successes.

Big Bang theory originally had 2 more seasons Parsons sheldon

After working for a scientific breakthrough his whole life, Sheldon wins a Nobel Prize. He even shares this accomplishment with his wife, Amy Farrah Fowler (Mayim Bialik). Penny becomes the head of Bernadette’s (Melissa Rauch) pharmaceutical sales team after years of making ends meet through waitressing. Also, as revealed in The Big Bang Theory’s finale, Leonard and Penny settle down and begin a family of their own. Meanwhile, Howard is now a father of two with his wife, Bernadette, and Raj, although still single, has learned to wait for a love that will accept him for who he truly is. From the group of outcasts introduced at the start of The Big Bang Theory, the show’s main characters have truly changed for the better — a complete 180.

Of course, these character developments are inevitable. These changes have kept The Big Bang Theory fresh throughout the years, avoiding stagnation and gradual loss of viewers. In the latter seasons, more interesting storylines have been developed out of the characters’ intertwining interests and identities. Moreover, by rejecting its own premise, The Big Bang Theory, despite its dark flash-forward, serves as a reflection of real life. As people meet and spend time with personalities contrasting theirs, they actually adjust and accommodate. Lastly, The Big Bang Theory also mirrors the change and maturity that come with the passage of time, emphasized by its characters’ reversal of fortune.

NEXT: Every Two & Half Men Actor To Appear On The Big Bang Theory