Few people change how the world thinks, but Srinivasa Ramanujan, born in 1887 in Erode, India, did exactly that. He is remembered for his brilliant discoveries about numbers.
Ramanujan was self-taught. He learned advanced mathematics largely on his own, working through a borrowed book of formulas.
In 1913, Ramanujan sent pages of his results to the mathematician G. H. Hardy in England. Then, in 1914, Ramanujan travelled to Cambridge University to work with Hardy.
Later, in 1918, Ramanujan was elected a Fellow of the Royal Society. In 1919, Ramanujan returned home to India. (Theorem: a statement in mathematics that has been proved true.)
Ramanujan died in 1920. Mathematicians are still proving and using results from his notebooks today.