She wants him to keep doubting his reality and one of the reasons it's so hard for Cobb to overcome this is that this doubt is linked to his love for his dead wife. So there's also a story about grief and overcoming grief in there too and this is why Maul is the antagonist and this is why she needs to be defeated and that's exactly what Cobb does in the climactic moment of the movie his subconscious manifestation of Maul is killed symbolically killing off the doubt that he was experiencing and thus completing his arc so now we get to the ending where Cobb arrives at the house where his children are staying he walks in he spins the spinning top but then he walks off into the garden to finally be watching a film and you want to know what it's really about all you have to do is pay attention to the decisions the protagonist makes the dilemmas that are presented to the main character and the choices they make in relation to those dilemmas practically always reveal the themes of the story and what's the last decision Cobb makes he decides not to wait until the spinning top stops he decides to finally go be reunited with his children so what's the point here the point of the story isn't whether or not it stops spinning the point of the story is that Cobb doesn't care anymore Cobb has accepted that he will never really know and he's learnt to appreciate whatever reality he's in he's a learn to stop doubting his reality and that's what the ending of Inception is really about.