Rob Kardashian and Khloe Kardashian in 2012 Credit: Dimitrios Kambouris/E/NBCU Photo Bank via Getty Images

Lost without Dad. Khloé Kardashian says Rob Kardashian started to feel "lost" following his father Robert Kardashian’s death. During an interview on Watch What Happens Live! on Sunday, January 17, the Kocktails With Khloé host, 31, explained that her reclusive younger brother, 28, didn’t truly deal with their father’s 2003 passing until six years later, when he graduated from college.

"I don't think he blames any of us [for his problems], we talk about stuff all the time," Khloé told host Andy Cohen. "I think Rob hit a dark place more so dealing with my dad's death that happened later in life."

Eight weeks after being diagnosed with esophageal cancer, Robert Kardashian Sr. passed away at 59 in 2003. Khloé explained that her dad always wanted Rob to attend college. The future Arthur George sock creator did just that and graduated from the University of Southern California in 2009. 

"He kind of had no direction, and I feel like he felt lost there, and I think that's when he started dealing with my father's passing," Khloé explained of Rob, who has gained 100 pounds over the past three years. “And then breakups and all this stuff happened, which I think added to other things in his life, but it's issues he had to deal with from the start that he just didn't.”

In 2009, while KUWTK ratings continued to skyrocket — along with the family’s worldwide fame — Rob dealt with a nasty breakup from Adrienne Bailon. According to the former Disney Channel star, Rob was “disloyal” during their relationship, but his fans have since blamed her.

"To this day, people will still say, 'You ruined Rob's life!'" Bailon later revealed to Latina magazine. “And I'll think, Damn, I was still playing with Barbie dolls when I met him."

Rob, who was hospitalized last month and diagnosed with type 2 diabetes, has been on an extended hiatus from the E! show — but according to his family, he'd like to make a comeback.

"I mean he was very happy doing the show for many years and he still says he misses doing the show," Khloé added on WWHL. During a chat with Maria Shriver last week, mom Kris Jenner also mentioned Rob’s desire to return.

"He wants to still come back and shoot the show, he just wants to feel good,” Jenner explained. “It's not that he doesn't want to be on the show, it's just he wasn't feeling good."

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