"Part Of Me" was written as part of the "Teenage Dream" album sessions (late 2009, early 2010). It leaked on December 30, 2010.
So, I don't wanna hear/read again that it's a copy of "Till The World Ends", CAUSE IT'S NOT. (they don't even sound similar). In any case, it's the other way around.
EDIT: Neither "dedicated" to Russel Brand. They changed the lyrics to fit her current situation. PERIOD.
It irritates me immensely that the media thinks this is a new song inspired by her divorce. It's not.
Me too. BUT that's exactly what Katy and her label wanted. No shade intended, as I love the song and am fine with the altered lyrics and whatnot. But this was definitely intentional.