Acharya Prashant explains that the Vedas are supposed to be the first book, meaning their authors did not have the benefit of hindsight. He likens this to a little kid just opening his eyes, marveling at the world and asking, "What's going on?" He cautions against judging the Vedas by their scientific rigor, as they didn't have labs, and science is an accumulative process. When human consciousness was first beginning to look around, there was nothing it could lean upon or turn back to for benefit; there were only questions. The speaker emphasizes that the glory of the Vedas lies in this spirit of questioning and inquiry. It is a process where they slowly keep rejecting all their assumptions and are ultimately left with only the questions. This spirit of inquiry, which ultimately rejects all suppositions, is what becomes the Upanishads. The journey does not stop at the questions. The Vedic process moves beyond the questions to enter the questioner. This, the speaker states, is the subject matter of the Upanishads. The entire process is an organic growth, starting from a place of awe and wonderment, and through a continuous rejection of assumptions, it culminates in the Upanishads, which investigate the questioner itself.