The Big Bang Theory had a set of fun, relatable characters who were defined by unique traits. In addition to the characteristics that set each one of them apart from the other, they all had quotes that live rent-free in Big Bang Theory fans' heads and perfectly defined their individual personalities.
Most of the quotes on the show were a mix of funny, thought-provoking, and heart-warming, but there were some that could only be defined as fitting for the characters who said them. These quotes from any other character might seem out of place but they're the perfect fit for the characters who said them.
Sheldon: "I'm Not Crazy, My Mother Had Me Tested."
Throughout the 12 seasons of The Big Bang Theory, Sheldon had to use some variation of this quote as a defense against people calling him crazy. It usually came up when he expressed an opinion or view that the others didn't agree with or thought was crazy, like when he and Howard were arguing about Wolverine being born with bone claws in the episode, "The Jiminy Conjecture."
His unique intellect often had people wondering if he was so crazy that even his mother had him tested as a child because she didn't understand his obsession with "science stuff." This quote perfectly summarizes everyone's first impression of Sheldon who has been called quirky, odd, and many other names because of his personality and behavior.
Howard: "I'm A Horny Engineer, Leonard. I Never Joke About Math Or Sex."
If there's any quote that perfectly describes Howard, especially in the earlier seasons of the show, it's this one from the episode, "The Hofstadter Isotope." He was proud of his Engineering degree and spoke often about having a Master's in the field and at the time, he relentlessly pursued women without much success.
On several occasions, Howard tried to use his scientific knowledge to get women, like the time he ended up crashing the Mars rover while trying to impress Doctor Stephanie. His character on The Big Bang Theory changed once he started dating Bernadette but he still used his Engineering skills to try and make himself seem more attractive, like the time he kept showing off about being an astronaut.
Raj: “I Haven't Cried This Hard Since Toy Story 3."
Raj is the sappy one in the group, often reduced to tears by a touching moment or a chick-flick. This quote from "The Apology Insufficiency" perfectly summarizes that aspect of his character when he was moved by Sheldon and Howard making amends with a high five.
One of the common jokes about Raj on the show was how soft he was, especially when it came to matters of the heart. He could cry over a movie or a book or anything that was remotely sweet or sad and this admission of him crying over an animated movie is a great example of that aspect of his personality and some of the saddest things about Raj.
Penny: "...There Was A Time I Never Would've Been Friends With Someone Like You, And Now You Are One Of My Favorite People."
Penny and Sheldon's friendship was one of the best in the entire show and the moment she said this quote in the episode "The Celebration Experimentation," was a beautiful one for their relationship.
Apart from highlighting her friendship with Sheldon, the quote almost summarizes Penny's life and her character's growth on the show. She was totally different from Sheldon and the other guys, but despite those differences in their personalities, they became the best of friends.
Bernadette: "At The Office, I Have Two Assistants! I Don't Even Know Their Names. I Just Call Them Thing 1 & Thing 2."
Bernadette said this line to Amy in the season 11 episode, "The Retraction Reaction," while they were bragging to each other about their career successes. Although she was describing her work life, the quote is a perfect fit for Bernadette's character, especially in the later seasons.
At first, Bernadette was a sweet, timid person who couldn't even tell a lie, but as the show continued she became scary and mean, especially at work where she was rather cruel to people, as evidenced by her quote, and everyone was scared of her.
Stuart: "Look At Me. I'm 37. I Sleep In The Back Of A Comic Book Store, And I Have The Bone Density Of An 80-Year-Old Man."
Before he turned his life around and his comic book store became successful to some extent, thanks to a tweet from Neil Gaiman, Stuart's life was the saddest on The Big Bang Theory. His comic book store was failing, his financial situation was terrible, and he often spoke of his many health issues.
His sad life and personality is summed up with this quote, which was—oddly—the tail-end of a toast he made at Howard's bachelor party. By the time The Big Bang Theory ended, some things had at least changed for him, for example, he was no longer sleeping in his store, but he still didn't have a place of his own.
Leonard: "When People Finally Do Notice You, They're Gonna Find Someone A Lot Cooler Than They Thought."
Leonard's speech to the graduating class from his former school had some touching advice directed at students who'd had a lonely childhood like him. He'd spent most of his life unnoticed, even as an adult, but it didn't stop him from pursuing his studies, getting an impressive career in Science, and also some of the best achievements on The Big Bang Theory.
Because he'd spent that time "becoming interesting," he had a group of friends who were just like him and stuck with him through anything. He even got into a relationship with a woman he never thought he'd be cool enough to date.
Amy: "I Promised Myself If I Ever Got Friends I'd Do Whatever They Said. Really, I'm Lucky You Found Me Before A Cult Did."
Once the group started warming up to Amy, she spent more time with Bernadette and Penny at their girls' nights, followed them around, and mostly did whatever they wanted to do. She did exactly what she said in her quote, even as the show continued.
The quote came about in the episode, 'The Space Probe Disintegration," when Sheldon and Leonard decided to be more accommodating of the girls and let them choose what they'd do for the day. When Penny realized that she was guilty of doing the same to Amy, Amy explained that she didn't mind and was just happy to have friends, which was a prominent feature of her personality throughout the show.
Mary: "Lord, Mary Cooper Here, Coming To You From Gomorrah, California."
Two things defined Mary Cooper on The Big Bang Theory; her love for her religion and her tendency to be judgmental. As a devout Christian, she believed in being a loving and kind person, which was why most of the other characters loved her.
However, she also had a judgemental side to her personality and a tendency to stereotype people, like the comments she made about Howard and Raj's religion and race, respectively. The quote that's a snippet of one of her prayers simultaneously shows her prayerful side and her judgment of the city where her son lived and their way of life.
Beverly: "I Know I'm Not The Warmest Of Parents, But It Was Time We Spent Together & Honestly, Those Are Some Of My Fondest Memories."
Leonard's complicated relationship with his mother, Beverly, had only slightly improved by the time the show ended. As she said in this quote in "The Conference Valuation," when Leonard confronted her about making him a test subject, she wasn't the warmest of parents.
Even though she didn't behave like most parents, she loved him in the way she knew how, which involved spending time with him while tracking his progress and making observations for her books.