You'll know everything by thi openishad. You have to hear this sanscrit chravana. Get clarity and conviction. That is chavana. And if all doubts have to be removed by thinking and asking questions, and manana remove all doubts, clarity and convictions. Once you have got clarity and conviction, bear down upon that clear and what you are clear about and convinced about, and make it into a living reality by meditation. The result will be we will not only know ourselves, but we will know ourselves as brahman. And by extension, we will know the reality of the universe.