What's confusing?
How many times have you watched the film Korri......just out of curiousity?
All through Reloaded we are told that choice is an illusion........people only believe they have choice, when in fact they don't. This was represented by the Merovingian when he sent the blonde woman in the restaraunt a piece of cake........he was controlling her.....she had no choice to make, he wrote a program that controlled her....taking away all choice.
The Oracle tells Neo "you have already made the choice......you are here now to understand why you made the choice".........then Neo asks why he can't see past Trinity being shot when she falls, why he doesn't see Trinity die. The Oracle tells him, "we can never see past the choices we don't understand"..............
Basically what it all means is.........Fate. Our destiny is pre-ordained.........if something is going to happen, it's going to happen....there is nothing we can do to change it.
On the architect's screens in the source are different choices Neo could make. Each time, the architect predicts the correct choice Neo could have made. Why? because the choice had already been made.......the architect understands why Neo made the choices he did so he can see past them. The Architect knew Neo wouldn't enter the mainframe........the architect knew Neo would choose to save Trinity.
This is where the illusion of choice came into play. Even though the architect already knew what was going to happen........he told Neo, "she is going to die and there is nothing you can do to stop it".......then presented Neo with the 2 doors. This was the illusion of choice........the architect already knew what door Neo was going to take.......but presented him with 2 options to give Neo the illusion that he had a choice to make ...........when in fact he had already made the choice because it was pre-ordained (fate)..........