Hilary Duff Stunned by Joel Madden's Break Up Behavior  7/11/07

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Hilary Duff was shocked to see ex lover Joel Madden hitting the clubs following their break-up - because he had always despised the Hollywood party circuit when they were dating.

The Lizzie McGuire star was stunned by the Good Charlotte rocker's outgoing behavior following their split in November 2006, and was left feeling she "didn't really know" Madden despite their two-and-a-half year romance.

She tells U.S. magazine Seventeen, "All of the going out he did after we broke up sort of shocked me. Like, that's just so out of character for him, and when we were together, he hated stuff like that, so I felt like I didn't really know him as well as I thought I did."

But the 19-year-old has not been put off finding love and still remains optimistic.

She adds, "I still want the cookie-cutter American dream - to get married, have kids, and have a house with a picket fence. I still believe that marriage can work."

Duff is currently single while Madden is dating socialite Nicole Richie, and they are reportedly expecting their first child together early next year (08).