But Cobb stole the top and locked it away! That was the whole point.
It's the opposite of that. After decades in limbo Mal laid the top down and locked it away herself. She actively chose for their dream world to be "reality". Cobb eventually realized Mal had lost her grip. He went into her subconscious where he was able to find her totem and start it spinning again. That was the inception.
Exactly. What Mal did made her believe Limbo to be the real world, what Cobb (Leo) did made her believe Limbo was the dream world it actualy was and then want to wake her up. Unfortuantly the spinning top's influence in the dream-world/limbo carried over into the "real
" world, drove Mal mad and made her kill herself believing she's simply going to wake up in the real
As Cobb himself says when you do implantation this deep it'll define
that person and virtually make them into a new person driven
to accomplish this "idea" that they had in their head and they would not rest
or be satisfied until he accomplised it. This is why Mal and Cobb struggled so much after waking up Mal was utterly certain
the "real world" was still a dream and the only way she could get to the real world was to wake up by killing herself. Now, her logic is flawed in that she should realize that the decades of time she's lived would mean she's in a deep
dream state, so deep that if she tried killing herself she'd be more likely to "wake up" in Limbo than she would the "Real Real World" but regardless of that the deep implantation meant she pretty much had no choice. Spinning that top convinced her
on a subconscious level that her world was not real.
This is why the "ending was a dream" people have it so wrong because the driving force of this movie was for Cobb to let go of Mal, let go of his regrets and get back home to see his kids. Mal was no longer good enough for him and he had to let her go to move on with his life. If the ending was a dream then this is bullshit because it means Cobb didn't get what he wanted and, pretty much, Mal got what she
The ending has
to be in the real world for the character arc of Cobb to make any sense and to be worth a damn; if he's in a even "deeper
" dream state, in a different version of Limbo or something along those lines then Cobb didn't get what he wanted and his coming to grips with the past and letting Mal go (doing both by killing her in Limbo) is all pointless. Also it does
matter than "even if he's still in a dream he got to see his kids" because seeing his kids in a dream wasn't good enough for him and not what he wanted.
He wanted to see his "real" kids, the kids he had always known. That the kids look (more or less) the same is meaningless and can be written off as simply movie slieight-of-hand. If they used noticably older kids then the audience wouldn't immediately recognize them. No real, good, indication is given in the movie on how much time has passed between Mal's death and the events of the movie, the conversation Leo has with his kids over the phone suggests that they're still pretty young, his son still young enough to think that mom is coming back home even though he's been told she's gone, for all we know only a year could've passed between when Leo left home and the events of the movie. Also the point seemed to be that he could not see his kids faces in the dream is because he didn't know what they looked like in that final moment; in a way we could probably extrapolate that seeing his kids' faces were his uber-totem. Seeing them told him, for sure, he was in the real world and what happened with the top didn't matter.
It's also worth pointing out, in conclusion, that I think Leo was back in as much of the real world as he thought he was in during all of the "real world" scenes througout the movie. As there's little reason to even believe anything
in this movie occured in the "real world."