My childhood was difficult because when my mother died, my religious sisters had a strong and lasting impact on me...as did the family's Jansenist views being in opposition to those of the Jesuits.
I was basically self-taught, being able to learn high-level mathematics and langauges quickly.
I was a religious thinker with several dramatic conversions interceded by my writing extensive treatises on mathematics and physical subjects.
At age 19, I created a mechanical calculator to check my father's sums and at age 16 I proved an important theorem involving conics in projective geometry (i.e. my "mystic hexagram").
Much of my later mathematics involving the properties of a cycloid is traced back to my attempt to alleviate a toothache via a sign from God.
Corresponding with Fermat, we created the mathematical theory of probability starting from Chevalier de Mere's problem of points.
Ah, I almost forgot about my "Arithmetic Triangle" of numbers and all the wonderful properties it contains.
Answer:
Blaise Pascal (1623 - 1662)