The novelization, unlike the game, begins with the immediate prelude to Starkiller's mission to Nar Shaddaa, rather than Vader finding him on Kashyyyk. The book explains around its halfway point that the apprentice didn't really know or care about where he came from, figuring that Vader had probably created him somehow in a biological experiment (which is kind of funny in light of the sequel's plot).
When he visits his old home that was trashed by Vader and the Empire, the apprentice has a Force vision where he sees the battle and his father's death from Vader's viewpoint. His first thought is to dismiss the vision as some kind of a fantasy with no real meaning, but the fact that he also has accurate visions of other events throws some doubt on this. He doesn't really seem to accept the flashback as complete truth until the climax of the book; before that point, he spends some time wondering what difference it made whether or not the Kashyyyk incident really happened.
As for why the apprentice would follow Vader from the perspective of the story as presented in the game, well, in Star Wars as well as fiction in general, people live through really horrible experiences and they get over it... but not always for the best. Still, while the novel outright states that he suppressed his memories of Kashyyyk, the game implies it, treating what he learns in the cutscene as if he never knew anything about his father.
"Grant Allen [...] had written a book about the Evolution of the Idea of God. [...] it would be much more interesting if God wrote a book about the evolution of the idea of Grant Allen." ~ G. K. Chesterton, The Everlasting Man
Last edited by TKA-001; 09-26-2010 at 07:23 PM.