At the start of disc 2 when you are Laguna in the Winhill village and you see Ellone for the 1st time as a child. Keep that in mind. Now, when you rescue Squall in the deseret prison and Zell or someone asks him 'did you cone here as Laguna in the dream world' Squall says no. But then when the White SeeD come to Balamb Garden to retrieve Ellone and Cid asks Squall and co to find her and then they go to the place where Squall has a fight with the G-Soldier Squall says "Ellone, that girl from the Winhill?". How did Squall know that if he didnt go to the dream world as Laguna in the Winhill, even if their stats were the same the story line follows that Squall didn't come to the prison as Laguna.