@Wolvenworks Remember he's still locked in the "this is a game and not real" point of view. That's why his mom called him a day dreamer.
What's strange to me is that he was only 18 when he died so he has lived in this world for almost as long as he lived in his original world. So it might be related to his regression that his mom pointed out in his flash back. Something that prevents him from maturing past a certain point? Endless Chuunibyou phase.