Born in Serbia in 1856 to an illiterate mother and a priest, Nikola Tesla was no doubt a genius. At college he showed how he could perform integral calculus in his head, prompting his teachers to accuse him of cheating.
During his first year at University he worked from 3am to 11pm every day, but later became addicted to gambling, losing all his allowance before winning it back and returning the balance to his family. He failed to graduate and worked as a draftsman.
During this time he had a nervous breakdown.