Interestingly, Euler had extraordinary powers of concentration. He could recite the entire [[Aeneid]] word-for-word. He could work amid noise and distractions. He could do phenomenal calculations in his head, which became very useful after he went blind in 1766.<ref>http://scienceworld.wolfram.com/biography/Euler.html</ref> | Interestingly, Euler had extraordinary powers of concentration. He could recite the entire [[Aeneid]] word-for-word. He could work amid noise and distractions. He could do phenomenal calculations in his head, which became very useful after he went blind in 1766.<ref>http://scienceworld.wolfram.com/biography/Euler.html</ref> |