Out of the six friends, Phoebe Buffay was the outsider that merged with the rest of the gang. She was eccentric and extraordinary - the qualities that served as a magnet for some guy like David, Gary, Mike.
Regina Phalange differed from Monica, Chandler, Rachel, Ross and Joey. She was friends with muggers, she lived in the street and also in Prague. That's why Rachel always assumed Phoebe would be the one to go. She was living far away, she was not related. She would lift right out. These characteristic features can be easily related to Luna Lovegood from the Harry Potter saga. A loyal friend with eccentricities.
While Luna was a witch who preferred reading her magazine upside down, Phoebe was a bohemian musician, who read tea leaves. Besides bright and funny sides, Phoebe and Luna shared a similar tragic past. They both witnessed their mothers’ death.
Given the fact that Friends tells a story of Manhattan muggles while Harry Potter is a story about British magic, it would be rather easy to guess whether the line comes from the sitcom or from the wizardry saga, unless they come from Phoebe Buffay or Luna Lovegood that is!