The Messenger of Allah (may Allah's peace and blessings be upon him) informed us of what was and of what is to come. The most knowledgeable among us is the one who memorized it best

The Companion ‘Amr ibn Akhtab (may Allah be pleased with him) reported that the Prophet (may Allah's peace and blessings be upon him) once gave a whole-day sermon. He performed the Fajr prayer then ascended the pulpit and addressed them until it was time for the Zhuhr prayer. He came down, performed the Zhuhr prayer then ascended the pulpit and spoke until it was time for the ‘Asr prayer.

He came down, performed the ‘Asr prayer then ascended the pulpit and spoke until sunset (the time for the Maghrib prayer). His sermon lasted the whole day from dawn to sunset. On that day, Allah, the Exalted, imparted to him some knowledge about the unknown events of the past and the future. So the Prophet (may Allah's peace and blessings be upon him) informed his Companions of what he had learned. The most knowledgeable of them were those who memorized well what they heard from him that day.