Madara said that finding out the history of shinobi is the reason he felt hopeless and left the village. And he learned it from the Uchiha's stone tablet.
But it was said before that the Rinnegan is also needed to read what is written on the Uchiha's stone tablet. So, if Madara only awakened the Rinnegan after he left the village and his final battle with Hashirama, how was he able to read the stone tablet without the Rinnegan?