But I'm not wondering about the age difference between Fischer and Saito--it's the difference between Cobb and Saito in the confrontation scenes that bookend the film. Saito and Cobb both entered limbo at or near the same time from level three, and after an unknown period of time when Cobb is brought to the table, Saito is a very old man and Cobb is not. If they had both been there for decades, Cobb should have been made to look far older. Even given the age difference between the two men, it looked like Saito had been in limbo far longer, when I don't think that he had based on the order and timing of events.
Oh okay. When you quoted civiclx he specifically mentioned Fischer and Saito, so I replied accordingly, but I do have the answer for the age difference between Cobb and Saito.
Okay. It is established that time is perceived differently as a dreamer travels further into a deeper level of a dream. The exact formula escapes me, but generally we can all agree that time in the Snow Fortress progressed much slower than in the very first level of the dream, which took place inside the white van. A few seconds inside the van is a much longer amount of time in the snowy fortress.
Saito was shot in the first level of the dream, and it is there that he died. Later on, Cobb died within the same van (he drowned). It's that amount of time between Cobb's death an d Saito's death that partially caused the difference in age between the two when Cobb found and rescued Saito. I don't actually remember the amount of time between Saito's death and Cobb's death though.
Another reason for why Cobb didn't seem to age much at all (or at all) is because he knew he was in limbo. As it was explained in the film, when someone stays in limbo for an extended amount of time, they lose their grasp on time and reality, and they begin to age. Saito has never been to limbo before, and I'd guess that in time he forgot that it was limbo and began to age.
Cobb on the other hand had been to limbo before and had been through the process with Mal. When he went after Saito, he knew he was in limbo, therefore he had control over his image.
When Saito finds Cobb on the beach and has him brought into his palace, Saito's guards note that the only items they found on Cobb were a gun and the spinning top. It is when Saito sees the top spinning (as well as a few choice words from Cobb) that he remembers that he is in limbo and that he isn't really an old man.
this movie can make you a bit
no one's calling you ignorant.
Dino !. Always calling people ignorant. 
