That is very cool, very impressive - beautiful. I suspect there are a lot of such "hard" problems with simlpe, eloquent solutions just waiting for the right mind to unlock them.

Somewhat related - are you familiar with Kim Peek, Daniel Tammet and other "savants"? Their mental powers in certain areas are really incredible, perhaps people like von Ahn are similar but simply more "normal". The brain has vast secrets.

According to Peek's father, Fran, Peek was able to memorize things from the age of 16-20 months. He read books, memorized them, and then placed them upside down on the shelf to show that he had finished reading them, a practice he still maintains. He reads a book in about an hour and remembers approximately 98% of everything he has read, memorizing vast amounts of information in subjects ranging from history and literature, geography, and numbers, to sports, music, and dates. He can recall some 12,000 books from memory. Peek can also do formidable calculations in his head, a skill that serves him well in his day job, where he prepares payroll worksheets. He has worked at a day workshop for adults with disabilities since 1969.

Peek did not walk until the age of four and still walks in a sidelong manner.[3] He cannot button up his shirt and has difficulty with other ordinary motor skills, presumably due to his damaged cerebellum, which normally coordinates motor activities. In psychological testing, Peek has scored well below average on general IQ tests; however he has scored very highly in some subtests. The mixed results have led to the conclusion that such tests are not an adequate tool to measure Peek's abilities.

Unlike many savants, Peek has shown increasing social skills, perhaps due to the attention that has come with being perceived as the "real Rain Man." His father says that his sense of humor has been emerging since 2004 or so. Also, he has developed well beyond the stage of being a mere repository of vast amounts of information; his skills at associating information he remembers are at least one of the signs of creativity. He still displays difficulty with abstractions such as interpreting the meanings of proverbs or metaphorical turns of speech. Although never a musical prodigy, Peek's musical abilities as an adult are receiving more notice now that he has started to study the piano. He apparently remembers music he heard decades ago and can play it on the piano, to the extent permitted by his limited physical dexterity. He is able to give running spoken commentary on the music as he plays, comparing a piece of music, for example, to other music he has heard. In listening to recordings he can distinguish which instruments play which part and is adept at guessing the composers of new music by comparing the music to the many thousands of music samples in his memory.

Pi
Tammet holds the European record for memorising and recounting pi to 22,514 digits in just over five hours.[3] This sponsored charity challenge was held in aid of the National Society for Epilepsy (NSE) on “Pi Day”, March 14, 2004, at the Museum of the History of Science, Oxford, UK.[4] The NSE was chosen to benefit from this event because of Tammet's experience with epilepsy as a young child. Professor Allan Snyder at the Australian National University said of Tammet: "Savants can't usually tell us how they do what they do. It just comes to them. Daniel can. He describes what he sees in his head. That's why he's exciting. He could be the 'Rosetta Stone'."

Language mastery
He can speak languages including English, French, Finnish, German, Spanish, Lithuanian, Romanian, Estonian, Icelandic, Welsh and Esperanto. He particularly likes Estonian, because it is rich in vowels. Tammet is creating a new language called Mänti. Mänti has many features related to Finnish and Estonian, both of which are Finno-ugric languages. Some sources credit Tammet as creating the Uusisuom and Lapsi languages as well.

Tammet is capable of learning new languages very quickly. To prove this for a Channel Five documentary, Tammet was challenged to learn Icelandic in one week, a language with a popular reputation as one of the world's most difficult languages to learn. Seven days later he appeared on Icelandic television conversing in Icelandic, with his Icelandic language instructor saying it was "not human." Segments of the interview, showing Tammet responding to questions in Icelandic, were televised on the American News show 60 Minutes.