Creativity is cheap. All you need do is concoct a stupid idea - that Venusians invented marshmallows, for instance - and you'll be creative. As for self-expression, you express yourself every time you break wind.
For this reason, no decent artist worries about originality. Shakespeare cribbed his plays from everyone from Plutarch to Marlowe; we remember Shakespeare, not for his originality, but for his craft. Raphael produced the most lovely paintings of 15th-century Florence, but not one of them was original - Raphael merely did what his teacher, Perugino, did, except that Raphael did it better.
Edward Ingram getting cranky and platonic in «Pop Idol Judges Understand Plato» in the Telegraph. (Many thanks to MGL @ (...) for the link.)