I dunno that seems a little harsh, it does say that he has spent 5 years studying Halliday and the Egg Hunt including playing of all the games Halliday idolised. I saw it more a case of once he'd made that breakthrough future breakthrough came more easily and he is helped by others that beat him to the breakthrough. It's not a case of he is suddenly has Jedi powers y'know because, there is definitely implied apprenticeship, the plot takes place over years there is time for growth understanding etc.