Nicole Richie has finally explained the reason behind her mysterious feud with her The Simple Life co-star Paris Hilton. The socialites had a much-publicised fall-out in January 2005 and have famously refused to divulge the reason behind their rift. But Richie now insists she steered clear of her former pal after a stint in rehab made her reassess her priorities. She tells Vanity Fair, "When I got out of rehab, I had to figure out what path to go down, and part of that included taking certain people out of my life. "I just decided I didn't want to be her (Hilton's) friend anymore. We're just two completely different people; we don't have that much in common."