Well, that douche from the band Creed also claimed he stopped listening to music when he recorded albums. Didn't seem to really do them much good...
Besides, playing other people's melodies is *really* normal. Before "pop" music in the 40s, pretty much everything was recycled music. Folk music is completely built around the idea that everyone uses the same chord progressions. The blues pretty much began as a bastardization of the folk sounds, and many blues songs themselves sound like other blues songs. Jazz music constantly lifts melodies from other sources. Take it forward into rock music, which created itself out of blues riffs. Psychedelia which rewashed a lot of world melodies. Punk music uses the exact same progressions that 50's bubblegum pop did. Then you've got hip hop which was completely built out of literally "stolen" melodies.
It's the essence of music. Very, very few people have *ever* come up with something completely original, the real genius and creativity comes from the way you recontextualize the music you've been exposed to.