On November 10 episode of MBC's television show 'South Korean Foreigners', Lee Ji-ahn made a guest appearance.
Lee Ji-ahn said, "My IQ score is 148, but Lee Byung Hun's is higher. All my family members are pretty smart."
She continued, "When Lee Byung Hun was in school, he used to be one of the top students in the whole school. He was also the class president. He was really popular."
She went on, "But I didn't really like to study. My test scores would go up and down pretty dramatically depending on whether I studied for the tests or not."
Lee Ji-ahn said, "He used to give me long lectures all the time. He would tell me off whenever I came home late at night as welll."
She added, "I had a curfew until I was in my mid-30s.", which surprised the hosts and other guests.
But the actress said Lee Byung Hun was a funny brother to her at the same time.
She said, "Lee Byung Hun was always trying to make our family members laugh. He liked making us laugh."