Do you know any famous mathematician who had a normal life before becoming famous ?

>Newton was born as a poor farm boy
Newton was actually wealthy, relatively speaking anyway. But yes he wasn't exposed to math until university.

IIRC Voevodsky failed out of high school and failed out of college. He started writing a mathematician in Harvard and the mathematician was so impressed he admitted him as a grad student. Then Voevodsky almost failed his qual exams despite revolutionizing the field he almost failed in. He later went on to win the fields medal.

Details of the story may be off just reciting from memory but it’s the gist.

Genius also requires a shit-ton of hard work. Don’t play down how much effort real geniuses put into their study

Also IIRC once he got kicked out of school he just read and went through a ton of math books.

Grothiendieck also independently rediscovered the labesgue integral and a lot of measure theory as an undergrad.

I think Banach was self-taught.

Einstein was above-average, but not brilliant.

Heaveside was an autodidact in mathematics too

Consider that a lot of "child prodigy" stories, especially nowadays, are made up and exaggerated a posteriori.

Yeah this is something that people rarely mention. Even von Neumann worked really hard. When you're good at something and get recognition for it it tends to make working hard easier. Snowball effect

With the exception of Tao and Perelman there are no 'child prodigys' in recent memory that actually did/do anything important.