“My theory about Inception is that while there are many interpretations, and ample evidence to support each and every one of them, my final conclusion is that it’s a really a simply story that becomes amazingly complex in people’s minds.
Cobb is a regular guy with 2 kids who is coming home from a business trip on a plane. His wife suffered from a mental illness, Cobb took her to 3 psychiatrists to try and get her help, but in the end she lost her mind, trashed their hotel room on their anniversary and threw herself off the building and killed herself which why she is so prominent in the entire movie. The movie starts when Cobb gets on the plane to go home. A big guy in first class (Eames) bumps Fischer and knocks his passport loose and it is given to Cobb. When Cobb sees the passport, he realizes who Fischer is and feeling sympathetic to Fischer he buys Fischer a drink and toasts his dad. Then he falls asleep on the plane.
Everything from the first scene with Saito to the last scene with Saito as an old man takes place entirely in Cobb’s mind, with the one exception of getting on the plane, which was real) When Cobb finally wakes up on the plane, he’s still on the plane and back in reality.
The thing that throws everyone for a loop is the spinning top, but the biggest clue isn’t the top, it’s the TRAIN.
The night that Mal kills herself she talks about “the train that will take them to where they want to go “and it’s the last thing she says before she jumps to her death. This is the reason that Cobb says he hates trains, and he has a damn good reason. It’s also a symbol for where he wanted to go: He wanted to die with her, not her first. This is the reason they are both on the tracks together about to die, and the reason he built everything in Limbo is because that’s what he wanted to do. In his dreams they did grow old together, but he struggles with the image of her all through the dream is because that’s the only place she now exists and she keeps interfering in everything because the dream is Cobb’s dream and all the other characters are projections of Cobb’s mind. He’s trying to tell himself that they aren’t real. This is why the train slams down the street trying to kill everyone.
In the end the entire dream is a struggle between Mal trying to tell Cobb that the dream is real and him trying to keep him asleep wake up vs. the image of his kids, who’s faces he can’t see because he is dreaming and they aren’t real. When Cobb wakes up, the people in the whole dream were just the people sitting in first class, everything is normal at the airport and when he gets home and sees his kids he really is home.
That’s pretty much it. It’s a love story.”