Responses
So basically, he did change his name in both timelines, but his past life's name was Hyoil > Iwol, and his current life was Han > Iwol.
In addition, certain details of the events up to when Iwol woke up in the same room as Jeho and Cheonghyeon at the start got changed because of the butterfly effect of the system changing one major event in Iwol's past.
As the story progresses, Iwol learns about the changed events and about the memories from his past life that he either forgot or the system hid from him.
So he doesn't have his current memory in this life? So he doesn't remember changing his name?