Sixteen months after Michael Jackson's death, his ex-wife Lisa Marie Presley finally opened up about their much-scrutinized marriage.

"I didn't understand my relationship with him," Presley, 42, confessed on The Oprah Winfrey Show Thursday.

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Though skeptics have labeled their 18-month marriage a sham, Presley insisted it was the real deal -- though she understands why Jackson's behavior might cause people to question its validity.

"To some degree, he was a master at manipulating the media," she said. "I understand that nobody really knew who I was. They just assumed I was going along with something he would be doing....I understand it better now. The manipulation was a survival tactic for him."

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After Jackson's death in June 2009, Presley said she's "come to have all this love again and understanding for him. I don't know why it had to take all that to have this happen. That upsets me a bit."

But Jackson's ex-wife admitted she didn't always have such warm feelings for the King of Pop, whom she divorced in 1996.

"I was very angry. I was so angry," she revealed. "I felt that we were so united, and then at some point he pushed me out."

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According to Presley, part of the reason she felt distant from Jackson was due to his increased drug use, which he attempted to keep a secret.

"I didn't really suspect and catch on until just before I filed for divorce. There was just an occasion, an incident where he had collapsed and he was in the hospital," she recalled.

Though doctors blamed it on a viral infection, Presley said that "every day there was a different report. And I couldn't tell what was happening. I couldn't really get a straight answer about what was happening with him, and I think we were all a little bit in the dark."

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Looking back, Presley wondered if she could have potentially saved her estranged ex-husband's life.

"I know it's naive to think that I could have, but I wanted to," she admitted. "Had I made a call, had I stopped being so shut off from him, had I just said 'How are you?' I really regret that I didn't."