July 9, 2003 ? She had his name tattooed on her body and carried a sample of his blood as a love token, but now Angelina Jolie says her ex-husband, actor Billy Bob Thornton, is a virtual stranger.

"We changed a lot in the two years we were married. I thought he was amazing. And, now I just feel like I don't know him," the actress tells ABCNEWS' Barbara Walters in an exclusive hourlong interview airing this Friday at 10 p.m. on 20/20. Jolie was 24 in 2000 when she married Thornton, who was 44. Their marriage may have been brief, but, if nothing else, it was intense.

They were known for their eccentric behavior in public. Thornton told the press they wore each other's underwear, and Jolie tattooed Thornton's name on her arm and in a more discreet area of her body.

Strange Symbols of Love

Jolie, who won a best supporting actress Oscar for Girl, Interrupted, talks with Walters about why she and Thornton carried samples of each other's blood as tokens of affection.

"It's not that crazy," the actress says. "It's like if you think about when you were like in high school. You know, it wasn't vials of blood; they were things that you put flowers in, pressed flowers in. It was a Christmas present from me to him a spot of blood in each pressed flower thing. It wasn't a vial, and it was a romantic thing you do, that was symbolic."

After the couple split, Thornton reportedly burned the blood samples in what he referred to as a "marital coffin."

Jolie tells Walters that she and Thornton are no longer friends. "It's like we just changed, we became very different people, and I wouldn't know what to talk to him about."

During the interview, Jolie also talks about dating and marriage. "I think I'll never get married again. I don't want to have a temporary father for my son," she tells Walters.