The unforgotten past

Alex shows up in the box with nothing in memory just like every other Greenie on the first day.

She gets up from the box and gets settled in the glade. She notices a boy. He's fit, has brown hair and light brown eyes but almost looked green when the light hit him. His name was Thomas.

She's seen him somewhere before, just cant remember where. But she knows shes seen him before.

Does he remember her even though their memories has been deleted?
Do they survive in the maze?

But more importantly; do they stand by each other the whole journey no matter how hard and difficult its going to be?