Descartes's Experiment to Find Certainty

In his book, discourse on the method of rightly conducting the reason, descartes says he's going to doubt everything i can possibly doubt. His project is to come to a hundred % certainty through reason. He doubts everything, but the only thing he finds that he can't doubt is that he exists. And this is where his famous phrase comes in, cogito ergosun, i think, therefore i am.