Today, Johnny Galecki is a superstar in the sitcom world, famous for his portrayal of Leonard in The Big Bang Theory. But when the show started, Johnny wasn't nearly as well-known, and the few viewers who likely remembered him from other projects couldn't have anticipated how much TBBT would impact his career.
Before he became Leonard Hofstadter, Johnny Galecki was David Healy on Roseanne, a role that spanned five years and even saw a revival in 2018 (Galecki appeared on the show then, too). Roseanne made its titular character a household name (and earned Roseanne Barr a fortune), but none of the supporting cast truly found fame until long after Roseanne ended (the first time). As for Johnny, after that series ended, he wasn't really looking for another sitcom—but luckily the role of Leonard drew him in.
Anyone who watched Roseanne in the early 1990s will remember Johnny Galecki as David Healy (well, at first, Kevin Healy). David starts out as a less-than-beloved love interest of Roseanne and Dan's daughter Darlene, but eventually, the two wind up together.
In the revival of the show, "David" makes an appearance, and his story is wrapped up as him being with Darlene and having two kids together. While he wasn't a main character in the series, plenty of viewers liked Johnny Galecki already when The Big Bang Theory began, and his old co-star even showed up in an episode, too.
Sara Gilbert and Johnny Galecki dated on Roseanne, but they also had a real-life romance before Sara realized she was a lesbian.
By the time The Big Bang Theory came around, Johnny Galecki had moved on from his sitcom era. At least, so he thought. During his very first interview on the set of TBBT in 2007, Johnny talked about the fact that he wasn't looking for another TV gig, but somehow it found him anyway.
It had been a decade since Roseanne, and Johnny was working on a play in New York. Chuck Lorre called him up, and although Johnny wasn't looking for a live-action show, he was intrigued.
He admitted he wasn't looking for another live sitcom show because he wanted to "mix things up" after spending five years in front of a live audience on Roseanne.
It seems that Johnny was open to new opportunities at the time, though, so he agreed to chat about TBBT. Initially, he was asked to play Sheldon but turned it down—even though Chuck had largely 'designed' the show around Johnny to begin with.
In that ages-old interview, Galecki said he was more "driven" to the role of Leonard, and after seeing Jim Parsons' performance as Sheldon, he decided he "couldn't hold a candle" to Jim's "incredible" performance.
Not that the gig of portraying Leonard was easy, though. During that early interview, Johnny and the rest of the crew were in the trenches with their character development, even visiting UCLA to learn more about physics and pick up some character mannerisms.
Johnny explained that they weren't trying to learn what the characters know, but they 'stole' mannerisms, wardrobe, postures, and interactions to infuse into their characters.
It was much different than Roseanne, of course, and the change was likely a welcome one for Galecki, who didn't seem super eager to return to sitcoms. Even his 2018 Roseanne appearance only lasted a handful of episodes (he appeared in four episodes of The Conners after Roseanne ended).
After The Big Bang Theory, Johnny Galecki had at least one project (A Dog's Journey), but it seems he's laid low ever since. Following the series finale of TBBT, Johnny had a very active personal life. In 2018, he was said to be dating Alaina Meyer; in 2019, they had a child together. By 2020, however, it seemed they had broken up.
That doesn't mean Johnny isn't busy being a dad, though. His Instagram showcases just a few of his adventures with his son Avery, from going onstage during a soundcheck for My Chemical Romance to adventuring in Disneyland and touring art galleries.
Despite sharing some of his life on Instagram, of all the cast members, Johnny seems to have kept the lowest profile post-TBBT. As of September 2023, his IMDb doesn't show any in-progress work, though he did have some producing credits in 2022 on the TV series Living Biblically.
Johnny also shared a 2021 project on Instagram; he voiced a character on a holiday radio program with Audible. While his project choices sure are interesting these days, Johnny clearly doesn't have to work to survive, so fans will have to be content watching his adventures play out on social media until (if?) he decides to get back into TV and film.