10 plot holes and inconsistencies you never noticed on 'The Big Bang Theory'

• There are a few minor plot holes and inconsistencies on "The Big Bang Theory."
• Some viewers have noticed that Sheldon was once referred to as a Taurus even though that zodiac sign doesn't match up with his birth date. 
• Also, Leonard supposedly has a serious snoring problem even though other characters have said that he doesn't snore. 
• This post contains spoilers from "The Big Bang Theory."
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Many shows have minor plot holes and continuity errors that only the most eagle-eyed fans catch. And although it focuses on a group of intellectuals, "The Big Bang Theory" is no exception.

To prepare you for the upcoming series finale, INSIDER compiled a list of a few of the most confusing moments and puzzling inconsistencies on "The Big Bang Theory" that you may have missed. 

Warning: Major spoilers ahead. 

SEE ALSO: 30 of the most-memorable moments from 'The Big Bang Theory'

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No one can decide how long the elevator has been broken.

Way back during season one, it is said that the elevator has already been broken for two years. But that doesn't really gel because, during season three, it's said that an experiment of Leonard's (that failed) broke the elevator seven years ago — which confuses the timeline.

The same actor has played two important characters in "The Big Bang Theory" universe.

"Young Sheldon," a spin-off of "The Big Bang Theory," premiered just two years ago. Fans of the franchise will know that Lance Barber, the actor who plays Sheldon's dad on "Young Sheldon," also appeared on "The Big Bang Theory" during season five.

Back then, he wasn't playing Sheldon's dad in a flashback, but an entirely different character: Leonard's high-school bully. Wouldn't Sheldon have pointed out that Leonard's former bully looked a whole lot like his deceased father? 

Why does Penny's dad's name change?

When Penny's dad is first mentioned on the show, she says his name is Bob. But when he visits a few seasons later, his name is Wyatt.