The Big Bang Theory Plot Hole That Still Bothers Fans

Much like those who adore the hit sitcom Friends, fans of The Big Bang Theory haven't stopped watching the show just because it ended. After a 12-season run, the popular comedy series came to a touching conclusion in May 2019, leaving audiences to fill the void by watching reruns ad nauseam now that Netflix is streaming all but the final season on demand.

While binge-watching a beloved show from the beginning all over again is a treat for viewers, it's presented an unfortunate trouble for the writers and creators of The Big Bang Theory: fans have uncovered plot holes and inconsistencies in the series' narrative. Twelve years' worth of show leaves a lot of tiny details to be forgotten by a large team of writers who were constantly bandying about new ideas to make people laugh instead of ensuring small facts were upheld seasons and seasons later. Still, astute viewers and ardent Big Bang Theory followers are somewhat unforgiving, and have spotted a plot hole they find rather bothersome.

Naturally, the fact being disputed has to do with Sheldon Cooper, played on The Big Bang Theory by Jim Parsons. The pedantic, perfectionist physicist is a stickler for detail, and would probably be quite distressed himself at the confusion surrounding his own birthday.

On the season 1 episode entitled "The Peanut Reaction," Penny (Kaley Cuoco) decides to throw Leonard (Johnny Galecki) a surprise birthday party. While she's trying to convince Leonard that he should celebrate his birthday by going to the Cheesecake Factory, Penny and Sheldon get into an argument about birthdays in general. Unsurprisingly, the scientist has no interest in celebrating them, and doesn't feel like Penny should force Leonard into celebrating his either.

Realizing she won't win an argument against Sheldon, Penny, who had previously calculated almost all of the guys' astrological signs and planned to do their horoscopes, eventually hits back with, "Blah, blah, blah — "typical Taurus." Being a Taurus would put Sheldon's birthday somewhere between April 20 and May 20. But there's actually something very wrong with Penny's statement here.

There's little mention of it again, considering Sheldon's stance on birthdays. That is, until The Big Bang Theory season 8. On that season, Penny again refers to astrology (another thing Sheldon despises), but this time she calls him a Pisces, which would put his birthday between February 19 and March 20. As it turns out, Sheldon is a Pisces, with the 200th episode of the series, "The Celebration Experimentation" from season 9, revealing his birthday to be February 26 when Amy (Mayim Bialik) decided to throw him a birthday party, much to his dismay. Further confirmation came from The Big Bang Theory's official Twitter page in 2016, when the account encouraged fans to wish Sheldon happy birthday in February.

While this is a small detail, anyone acquainted with Sheldon Cooper will be able to tell you that this mistake would still irk him endlessly, particularly considering it pertains to him. Years of experience with Sheldon would also tell us that if Penny had simply made an honest mistake, he would have immediately corrected her when she called him a Taurus — and probably never let her forget the error either. Sheldon may consider astrology to be complete hokum – and its believers to be participating in the "mass cultural delusion that the sun's apparent position relative to arbitrarily defined constellations at the time of your birth somehow affects your personality" — but that doesn't mean he wouldn't know which star sign corresponds with which dates, considering his eidetic memory.

Thus, we must come to the conclusion that the Big Bang Theory creative team must have already assigned a birthday window to Sheldon on the very first season before deciding to address it again later on, and forgot to check their character boards throughout the years.

Fans are pretty unimpressed by the inconsistency, with many taking to Reddit to express their grievances (via Metro UK).

"Wait, how the hell can Sheldon be both a Taurus and a Pisces? Penny switches between the two halfway," one user wrote. Another another responded, "Yeah I noticed that – obviously a mistake. Sheldon would've corrected Penny the first time if it was simply a case of her not knowing his birthday." One other fan pointed out that Sheldon would be "so mad" people even debating his astrological sign given he "thinks horoscopes are trash."

Considering the later confirmations, we can assume Sheldon's February birthday is the correct date, but maybe we should give the writers a pass when it comes to the season 1 flub. After all, with all the work that went into the show over so many years, small details like this are bound to fall through the cracks. No harm, no foul, right?