MBC's "Infinite Challenge" was one of South Korea's most beloved variety shows, making viewers laugh week after week during its long run. But years after the show ended, several of its best-known cast members are revealing the intense psychological pressure they endured behind the scenes. Haha recently said the stress of filming the hit program became so severe that, looking back, he believes he was experiencing panic disorder. His account follows similar revelations from former castmates Jung Hyung-don and Jung Joon-ha, who have spoken about anxiety, sleepless nights and the emotional toll of trying to deliver laughs every week. Appearing on KBS 2TV's "Boss in the Mirror" on Sept. 6, Haha was asked by comedian Park Young-jin how he had managed to survive for so long in weekend variety television. "Popularity isn't something I can decide. Viewers' reactions are what matter," Haha said. He then recalled the anxiety he felt ahead of the weekly "Infinite Challenge" shoots. "We filmed every Thursday, but because of the pressure, my heart would start pounding from Tuesday evening," he said. "Lo