The only thing that I'm missing in Inception is why was Saito old in the opening and closing scenes of this great movie?
Both Cobb and Saito land in Limbo in (presumably) the same moment and Cobb spent (presumably) a very long time to find Saito, long enough for Saito to age about 40 years; however, Cobb remained the same age.
What caused such a significant difference between ages of both characters in Limbo despite them being roughly the same age when they entered and entering Limbo at the same time?