... creativity must be original, meaningful, and surprising. Original in the sense that the creator is rewarded for transcending expertise, and going beyond the standard repertoire. Meaningful in the sense that the creator must satisfy some utility function, or provide a new interpretation. This constantly raises the bar of what is considered useful, and puts immense pressure on creators to find new meanings. Finally, creative products must be surprising in that the original and meaningful creative product must be surprising not only to oneself, but to everyone. This is exactly how the United States Patent Office evaluates new applications. Original and meaningful ideas that could have been created by any expert in the field are considered "obvious" and are therefore unpatentable. Creative products— such as the discoveries of Galileo and Leeuwenhoek— are surprising to everyone, novices and experts alike.
This keys into something I come back to often: how the New Thing is surprising, and not always in a pleasant way. Sometimes it's jarring and ugly, because we haven't yet developed the proper eyes for it (Eraserhead). Sometimes it's lovely in a way we didn't know things could be lovely (Star Wars). Hence the function of the good critic: to defend the new thing because it rattles our cage a bit, although that should not be the only thing it does.
Creativity has to be original, meaningful, and surprising, and the problem with all three of those things is they are often the very things we are trained to guard against, ignore, or misinterpret.