RELATED: The Saddest TV Episodes of All Time. During a recent “Actors on Actors” interview for Variety with Elizabeth Olsen, Cuoco shared some of the sage advice she got Ritter, who she said was her “entire world” while on 8 Simple Rules. Ritter had been starring on TV for 30 years by the time he met Cuoco on the show (which was originally called 8 Simple Rules… for Dating My Teenage Daughter until his death). Of course, he was also known for Three’s Company and the Problem Child movies. “I remember conversations when I was 15 years old where he said, ‘You have to remember when you’re on a set, it’s like a tree. Number one’s here, and any way you act is all trickling down that tree. You can be a boss, you can be a great actor, you can get work done, but you can just be nice,’” Cuoco recalled Ritter telling her. “The respect and the kindness and the joy he brought to that set, it was unbelievable,” Cuoco previously told Variety in Feb. 2021. She said that Ritter told her he thought she was “going to go places,” so he introduced her to his management team. “In the future, if I was that number one, I knew how I was going to run my set,” Cuoco recalled thinking. RELATED: How Old 100 Iconic Stars Would Be If They Were Alive Today. It seems Cuoco has taken Ritter’s advice now that she is number one on the call sheet. Zosia Mamet, Cuoco’s co-star on The Flight Attendant, which she also executive produced, told Variety that Cuoco created a welcoming environment on the set of the HBO Max series. “It’s such a trickle-down situation. The captain of the ship—the way they are infects everybody else,” Mamet said. “And it was so clear that Kaley was so proud already of what we were doing. Everyone here matters. Everybody here is a part of this process.” For more celeb content delivered straight to your inbox, sign up for our daily newsletter. In Sept. 2018, Cuoco told Entertainment Tonight that she still gets chills when Ritter’s name comes up because she “loved him so much.” On Sept. 11, 2003, Ritter was rehearsing on the set of 8 Simple Rules and fell ill. He was reportedly vomiting, experiencing nausea, and feeling his chest tighten, according to the Los Angeles Times. In the midst of his illness, he called Cuoco over and said he wanted to talk to her. Cuoco said he told her, “I want you to know I love you,” and he hugged her. That was the last time she saw him. He died that night at age 54 of an aortic dissection. Today, the 8 Simple Rules cast continues to honor Ritter and keep his memory alive. “Thank you for continuing to me make me laugh every single day,” Cuoco wrote on Instagram on Sept. 11, 2020, the 17th anniversary of Ritter’s death.ae0fcc31ae342fd3a1346ebb1f342fcb Martin Spanjers, who played Ritter’s son and Cuoco’s younger brother on the show, wrote a lengthy tribute to Ritter on Instagram that day as well. “A lot of people will ask me, ‘What was John Ritter like?’—I will respond with something like: He was the greatest. The most kind, genuine, loving, and yes—hilarious person,” wrote Spanjers. “Whether you were a random fan approaching him or the head of ABC, he would show you the same respect and gratitude with his time…looking you in the eye, joyful, and remaining incredibly present.” RELATED: John Travolta Shares One of the Hardest Things About Losing Kelly Preston.