Rowan did not need to delve into the Memory of Primordial Life to find his answers, such a venture would come with unnecessary risk that he was not yet willing to take, because, unlike Seed and Elura who could not detect what he was, a Primordial would not be making that mistake.
What he needed was a guideline to show him the road to his past, and with it, he could build the present and his future. In the matters of understanding his powers, Rowan was coming to the realization that the only ones who could teach him anything truly valuable to him would have to be the Primordials, it was not just a matter of strength, there were many Old Ones stronger than him, it was just that his potential was many times greater than anyone else in reality except the Primordials.
