The Big Bang Theory may get all the blame for failing Penny and

completely snubbing her biggest goals and ambitions, but it also deserves

credit for Sheldon Cooper’s incredible transformation throughout the show’s run,

and Penny is once again the one to thank for it.

Initially introduced to the series as a relatively trivial character who

was supposed to make a striking contrast with Sheldon and his group of friends,

Penny had a huge impact on the way that Sheldon eventually started seeing his surroundings and reconsidering his life’s twists and turns.

Ironically, Sheldon seemingly knew Penny for much longer than he thought, and Young Sheldon confirmed it years ago.

In Young Sheldon’s season 3 episode 10 titled Teenager Soup and a Little Ball of Fib, the titular character is seen pretending to be sick just to avoid going to a swimming pool which, as he believes, was full of bacteria and all kinds of germs.

At night, Sheldon has a dream of himself standing in front of the swimming pool which is trying to convince him to swim in there for a while and see that there was nothing for him to be scared about.

To all the viewers’ surprise, Sheldon falls for the swimming pool’s temptation and comes closer to the water without diving into it yet, though it’s still quick to grab him and take inside the pool. Such a turn of events appears to be a real nightmare for Sheldon who then wakes up in cold sweat.

Many viewers may have never paid attention to it since it was nothing but a brief scene, yet the swimming pool talks with the voice of Kaley Cuoco, The Big Bang Theory’s Penny’s actress who for some reason wasn’t mentioned in the credits for the episode.

Still, Cuoco’s short cameo role couldn’t be a better fit when it comes to her character’s relationship with grown-up Sheldon in the original series.

Initially treated unfairly by Sheldon, who always thought of Penny as quite a mediocre person, the latter actually was the one to make Sheldon leave his comfort zone and try something completely new. And it eventually convinced Sheldon of being lucky to have Penny by his side.

While Leonard, Howard and Raj have spent years tolerating Sheldon before Penny came around, the quirky physicist’s friends just got used to the fact that it was almost impossible for him to ever change his habits, while Penny was persistent enough to show Sheldon that his point of view wasn’t always the right one.

Just like The Big Bang Theory’s Penny encouraged Sheldon to take a risk every so often, the same way Penny’s almost unnoticed cameo in Young Sheldon gave the character’s younger version an incentive to go for it even if it seems scary at first.