A good argument! But that Light was the 'real' Light. He was different than the Light we were shown before he got the Death Note. Just rewind back to the first few episodes before the Death Note was dropped on the Earth. The Light that we saw before that, was he consistent with the Light we saw when he lost his memories? He was waaaayyy different than the latter part. His 'lost-memory' personality was far too idealistic than his 'beginning' self. Atleast that's what I think...
Well, Light also told Ryuk before he got his memory of The Death Note erased, that "his old self" will help L with the investigation.
And we didn't really get to know how Light was in the beginning.
Edited by Mixer, 09 October 2015 - 04:29 PM.