Kim Kardashian was just 11 years old when she first heard her father, Robert Kardashian, talking about Caitlyn Jenner, then known as Bruce, wearing women's clothing.
"I overheard my dad and his friends talking about Bruce cross-dressing and I always thought he was just being a hater [of] the new husband, and he was jealous and made this up," she told Ellen DeGeneres Wednesday. "So I totally let it go and I didn't think about it again."
But in her early 20s, after moving back in with her mom, Kardashian walked in on Jenner in the garage dressed in women's clothing. Kim panicked, packed a bag and stayed with sister Kourtney Kardashian for the rest of the weekend. The two watched "Oprah" episodes to try and understand things better.
Kardashian has been a vocal supporter of Jenner since she came out as trans during a "20/20" special back in April. At the time, Jenner revealed Kardashian was one of the most supportive of her children, thanks in part to Kanye West.
"They were talking about it and [Kanye] said to Kim, 'Look, I could be married to the most beautiful woman in the world, and I am. I could have the most beautiful daughter in the world. I have that. But I'm nothing if I can't be me. If I can't be true to myself, they don't mean anything.'"
While with Degeneres, Kardashian echoed these comments.
"It's not really for us to judge," she said. "If that's how Caitlyn wants to live her life, then I support it, and I'm so happy for her and I'll try to do whatever I can to make it an easy transition for the other family members."