Or, at least, what makes our brain unique, even compared to our primate relatives? To try to address this question, we will go back to the very beginning, and we will dive into the fascinating process of the human brain development because it is at the roots of human brain evolution! And as our brain is still keeping a lot of secrets, we will also put ourselves into researchers shoes and see how they try to tackle this difficult question, using very diverse technologies, from human genomics to stem cell biology to neural circuit studies.