[MrGaryy]

I think the ending was not reality, it was a dream.

My theory is that the entire film was a dream from when Cobb was put to sleep in Mombasa. First of all, the chemist told them that only a very strong kick could awake someone from that deep of a sedation, yet Cobb woke up very easily, naturally almost. Also it was the only time during the entire movie that we didn't see Cobb's totum fall over, meaning there is no confirmation he ever actually woke from that dream.