In a look back at The Big Bang Theory, even the show creators admitted that Kaley Cuoco’s character, Penny, was a tad cliched as she started as the walking embodiment of the dumb blonde stereotype.

Chuck Lorre, who famously wrote hit shows like Two and a Half Men, explained that the role of the show’s female lead went through a few stages of development. However, even when it initially aired, Penny was still a work in progress. At first, in the show’s unaired pilot, a different character named Katie was front and center but didn’t quite capture what the creators were going for.

They wanted their female lead to be less judgmental than originally pitched, so they began writing Penny. It wasn’t perfect right away, though, and Chuck described her early characterization as a “goofy blonde who says foolish things.”