I've read that one too, but I don't particularly like it. P=NP implies only that all problems which can be verified in polynomial time can also be solved in polynomial time, not necessarily that it can be solved as quickly, nor that it can be solved easily.

Perhaps writing a piece of music is also done in polynomial time, but it requires more training (more advanced algorithm)? Or, perhaps, the time complexity is x^3 for writing, instead of x for appreciating.