Daniel Tammet is author of two books, Born on a Blue Day and Embracing the Wide Sky, the latter of which came out in January. He is also a linguist and holds the European record for reciting the first 22,514 digits of the mathematical constant pi. Scientific American Mind contributing editor Jonah Lehrer chats with Tammet about the way his memory works, why the IQ test is overrated, and a possible explanation for extraordinary feats of creativity.