Paula Abdul's behavior has fascinated the public in recent years, and apparently Simon Cowell is no different.

Her fellow American Idol, and now The X Factor, judge chatted with Redbook about the singer's sometimes confusing ways, telling the mag:

    "From the minute I met Paula, I was fascinated by her. She's a complex person, but – this is going to sounds very American – she's got a great heart."

Aw! Cowell, 51, said it works that he and Abdul don't always get along. "I do really like people who disagree with me," he said. "Probably my best friends in the world are the people I argue with the most, because they don't always say what you want to hear."