Kevin Sussman Reveals the Moment Stuart Began to Change on ‘The Big Bang Theory’

When Stuart Bloom first appeared on The Big Bang Theory, he was a surprisingly confident comic book store owner — confident enough, in fact, to ask Penny out and actually land a date with her. The longer Stuart stuck around, though, the more that confidence seemed to disappear. Over the course of the series, he became increasingly shy, insecure, and down on his luck, eventually seeing himself as almost irrelevant compared to the rest of the gang.

Now, on Stuart Fails to Save the Universe, that slow erosion of Stuart’s confidence has become even more interesting. He may still see himself as the guy least likely to save the day, but with the fate of the universe suddenly resting on his shoulders, Stuart is being forced to confront just how much of that diminished version of himself he has come to believe.

So what happened? According to Kevin Sussman, Stuart’s slow regression was no accident — and he can pinpoint the exact moment he believes everything started to change.

Warner Bros.

“I can tell you what I was told by one of the writers of Big Bang,” said Sussman. “As the other central characters evolved and got moved up in their careers and got into good, long-term, healthy relationships, they used Stuart as a counterbalance. So that as they were evolving, Stuart sort of de-evolves.”

In fact, the actor can pinpoint the exact moment Stuart became the Stuart we know and love today, and it happened on a whim.

“There was an early episode, Season 1, where I improvised one little line. It was after Penny (Kaley Cuoco) had dumped me, and she comes into the store. I think she’s looking for Leonard’s (Johnny Galecki) address or something. I don’t have it, and she turns, she’s walking away, and under my breath, I said — which was not in the script — I said, ‘I love you,’” revealed Sussman. “And Chuck Lorre, the creator, and the writers laughed and stuff, and I feel like that was the beginning of the de-evolution of Stuart, which I was welcome to, because that sort of troubled character led them in a direction that gave them lots of stuff to make jokes.”

Stuart’s sad journey became comedy gold for Sussman, giving him some of the character’s funniest — and most brutal — lines. “Later season where Stuart has one of my favorite lines, where Sheldon asks him how he’s doing, and Stuart says, “‘My therapist killed himself today. Blamed me in the note.’”

“I had lots of really, really funny lines like that, that I don’t know if I ever would have gotten the pleasure of doing had Stuart stayed the more competent comic book store guy,” explained Sussman.

Stuart Fails to Save the Universe, Thursday, HBO Max