I had never heard of Jim Parsons until I watched BBT but, his performance as Sheldon Cooper should be recognized as one of the greatest in TV history and the individual responsible for casting him should be considered a genius. Jim was born to play Sheldon. No other actor could’ve owned this character the way he did. I hope he continues to share his talent with audiences in other ways!
On March 13, 2017, CBS ordered the spin-off Young Sheldon series. Jon Favreau directed and executive produced the pilot. Created by Lorre and Molaro, the series follows 9-year-old Sheldon Cooper as he attends high school in East Texas. Alongside Armitage as 9-year-old Sheldon Cooper and Perry as Mary Cooper, Lance Barber stars as George Cooper, Sheldon's father; Raegan Revord stars as Missy Cooper, Sheldon's twin sister; and Montana Jordan as George Cooper Jr., Sheldon's older brother. Jim Parsons reprises his role as adult Sheldon Cooper, as narrator for the series. Parsons, Lorre, Molaro and Todd Spiewak will also serve as executive producers on the series, for Chuck Lorre Productions, Inc. in association with Warner Bros. Television. The show's pilot episode premiered on September 25, 2017. Subsequent weekly episodes began airing on November 2, 2017 following the broadcast of the 237th episode of The Big Bang Theory.
After Neil Gaiman tweets about Stuart's comic book store, it becomes very popular, and the crowds upset Sheldon. Stuart hires an assistant manager named Denise and she impresses Sheldon with her comic recommendations. Amy goes to her for information on comics to connect to Sheldon but when she tries to tell him, he says he's talked enough about comics with Denise. The store's popularity causes Stuart to be unable to babysit for Howard and Bernadette's date night. They try to have another at home, but Stuart shows up so they hurriedly go out. Meanwhile, as Raj sets up a telescope, Penny sees a new comet. Raj takes sole credit for the discovery, angering Penny. Leonard tries to defend her but feels sorry for hurting Raj's career. Penny confronts Raj herself and he agrees to share credit after Penny doesn't give in like Leonard.
In November 2016, it was reported that CBS was in negotiations to create a spin-off of The Big Bang Theory centered on Sheldon as a young boy. The prequel series, described as "a Malcolm in the Middle-esque single-camera family comedy" would be executive-produced by Lorre and Molaro, with Prady expected to be involved in some capacity, and intended to air in the 2017–18 season alongside The Big Bang Theory. The initial idea for the series came from Parsons, who passed it along to The Big Bang Theory producers. In early March 2017, Iain Armitage was cast as the younger Sheldon, as well as Zoe Perry as his mother, Mary Cooper. Perry is the real-life daughter of Laurie Metcalf, who portrays Mary Cooper on The Big Bang Theory.
With Melissa Rauch saying goodbye to Bernadette Rostenkowski-Wolowitz after joining the show in season three and becoming a series regular in season four, she's already begun to carve out new gigs. Not only did her indie film Ode to Joy make its film festival debut this part April, but she has another film, Steven Soderbergh's The Laundromat co-starring none other than Meryl Streep, in post-production, due for a 2019 release. While wrapping up filming on TBBT, she landed her next TV gig, playing Shira, wife of Paul Scheer's Keith on Showtime's recent Wall Street comedy Black Sunday. With the show recently renewed for a second season to debut on the cable net in 2020, it's looking likely she'll be back with greater availability.
Howard and Bernadette learn their second child will be a boy, leading Howard to doubt whether he can be a good father to a son. He and Sheldon go out in the desert to test launch a model rocket, but it explodes, causing him further doubt. On the way home, Howard does a good job coaching Sheldon to drive them home, for which Sheldon tells him he will be a good teacher to his son. Leonard's mother Beverly begins talking to Penny as a friend and confidant, troubling Leonard, especially when he learns that Beverly told Penny that she was proud of her, a level of praise she never bestowed upon Leonard himself. When Leonard confronts Beverly, he is touched when she says that of all of her children's spouses, Penny is the one by whom she is most impressed and that, for this, she is indeed proud of him. Meanwhile, Raj helps Bernadette turn baby girl clothes into boy ones.
In the third-season finale, Raj and Howard sign Sheldon up for online dating to find a woman compatible with Sheldon and discover neurobiologist Amy Farrah Fowler. Like him, she has a history of social ineptitude and participates in online dating only to fulfill an agreement with her mother. This spawns a storyline in which Sheldon and Amy communicate daily while insisting to Leonard and Penny that they are not romantically involved. In "The Agreement Dissection", Sheldon and Amy talk in her apartment after a night of dancing and she kisses him on the lips. Instead of getting annoyed, Sheldon says "fascinating" and later asks Amy to be his girlfriend in "The Flaming Spittoon Acquisition". The same night he draws up "The Relationship Agreement" to verify the ground rules of him as her boyfriend and vice versa (similar to his "Roommate Agreement" with Leonard). Amy agrees but later regrets not having had a lawyer read through it.
Amy and Howard begin collaborating on a neuroprosthetics project, upsetting Sheldon and Raj, who feel they are not spending as much time with them. When they seek solace with an annoyed Bernadette, she exploits the situation to trick Sheldon into doing Howard's chores. Penny successfully employs the approaches recommended in one of Bernadette's parenting books to deal with Sheldon, but Leonard believes she is coddling Sheldon too much. Sheldon and Raj resolve the issue of missing their significant others by spending time together.