When Jim Parsons first graced our TV screens as Sheldon Cooper in The Big Bang Theory, he had a style all his own. Neurotic but endearing, Sheldon boasted a Mensa-recognized intellect. He arrogantly flaunted this intellectual superiority as undisputed fact, yet still managed to come off as a lovable sitcom character — one who was generous with the unique information stored in his cranial crevices. Of course, we're talking mostly about scientific data involving wormholes and string theory, because Sheldon is a theoretical physicist at Caltech.

Sheldon was also riddled with anxiety and socially inept. But it didn't matter, because he was academically brilliant. And he certainly had no time to pursue anything romantic.

Sheldon wasn't even interested in going down that laborious romantic road of inevitable doom, and displayed little to no understanding of the adult relationships that surrounded him, such as Leonard (Johnny Galecki) and Penny (Kaley Cuoco), or Howard Wolowitz (Simon Helberg) and long-time love Bernadette (Melissa Rauch). Sheldon existed in a perfect bubble of childlike comfort, peeking out occasionally to attend a Star Wars convention or some other geek-o-rama. Otherwise, he couldn't even be bothered to leave his sacred spot on the couch, a place where he could live in the comfort of his own brilliant and self-satisfied mind.

Then in the fourth season, Sheldon began a relationship with neurobiologist Amy Farrah Fowler (Mayim Bialik). Although this development was contrary to Sheldon's presumed asexuality, audiences bought this story arc because it didn't actually involve any romance. Instead, their union was characterized by Sheldon's extreme neurosis, such as the infamous “Relationship Agreement” to verify the ground rules of being boyfriend and girlfriend.

Within these rather strict and impersonal rules, Sheldon and Amy's coupling seemed like little more than an elementary school relationship comprised of sweet glances and hand holding. But upon closer inspection, Sheldon's dynamic with Amy was adorable in a fascinating way; they bickered like an old married couple, and enjoyed a genuine friendship that felt unique to sitcom television — because it wasn't about sex. It wasn't the tired "Ross and Rachel" storyline from Friends. That is, until it was.

Along with milestones that felt appropriate to the show, like Sheldon listing Amy as his emergency contact, and telling Amy that if he were ever stranded on Mars, she'd be the only person he'd want to be stuck with, he started to do things that suggested a frightening and full-on personality transplant. He said the words "I love you" out loud. He "wooed" Amy when they broke up, and got jealous when other men came into the picture. Essentially, Sheldon became Ross Geller.

And then came the sex.

Sheldon and Amy's relationship went to the next level in "The Opening Night Excitation," which aired last December. This is a very strange episode in that it's absolutely not about science, but instead focused on the new Star Wars movie release, and Amy's birthday — which happen to fall on the same day. After Obi-Wan Kenobi visits Sheldon in his dreams and talks sense into him, Sheldon decides to spend Amy's birthday with her instead of seeing the movie with the guys. He also decides to give Amy a special birthday present: the "gift" of his genitals.

This "coitus," as Sheldon refers to it, is momentous for The Big Bang Theory. It also never should have happened.

Post-coitus, Sheldon enjoys himself like any regular guy would. The problem is that Sheldon is not regular. He was always so wonderfully irregular. He was among the most delightfully peculiar TV characters in modern memory, along with Kramer (Michael Richards) in Seinfeld, April (Aubrey Plaza) in Parks and Recreation, and Tina Belcher (voiced by Dan Mintz) in Bob's Burgers.

Now that Sheldon has lost his virginity, The Big Bang Theory will not go down in history for introducing a fantastic asexual character whose passion for science was the core of his very existence, and whose personal life was on the backburner where it belonged. The show will be remembered for re-writing said character as a guy's guy whose future will probably include marriage, and all that boring "adult" stuff that screams normality.

The Big Bang Theory returns for a 10th (and maybe final?) season this fall. And when it does, we'll likely have a Sheldon we barely recognize. He's already less obsessed with scientific theory, looser in how he carries himself, more jokey and less ignorant of humor and sarcasm. This is not the neurotic Sheldon we know and love. Suddenly, there is very little that sets The Big Bang Theory apart from other sitcoms.

And that's why I hope this is the show's final season. The Big Bang Theory frankly needs to end — because it's no longer fulfilling the premise that it so boldly introduced when it began.