Rene Descartes

If you don't have a favorite mathematician, and I'm guessing most people don't, I would suggest Rene

Descartes (Renay Daycart). He looked like a musketeer and, in fact, was a soldier for a time. He was sickly as a child and allowed to stay in bed for hours after everyone else had gotten up. He liked that idea so much, he just stuck with that routine pretty much the rest of his life. In math, he came up with the graphing on the x and y-axis thing that anyone that ever makes it through algebra knows about. It combined algebra and geometry. Pretty impressive. 

He was also a philosopher But, he is probably most famous for one particular line. and maybe most famous line was "I think, therefore, I am". Seems pretty obvious, but it made him famous. Seems pretty obvious, but it made him famous. What can I really be sure of in life? Maybe everything I think I experience is fake. But the fact that I am thinking right now means that at least I myself must exist. 

. . . I noticed that whilst I thus wished to think all things false, it was absolutely essential that the "I" who thought this should be somewhat, and remarking that this truth "I think, therefore I am" was so certian and so assured that all the most extravagant suppositions brought forward by the sceptics were incapable of shaking it, I came to the conclusion that I could receive it without scruple as the first principle of the Philoslophy for which I was seeking.

His last job was to teach philosophy to the queen of Sweden. It was early in the morning so he couldn't stay in bed on those mornings, but still, a pretty good job.