Nunca foi objetivo principal de Sam se tornar um meistre, com certeza foi por isso que ele foi para Oldtown, mas essa foi uma missão paralela.
SAM: I wanted to ask you something. To ask something of you. Send me, Gilly, and the baby to Oldtown so I can become a Maester. That’s what I’m meant to be, not this.
JON: I need you here, Sam. If you leave, who’s left to give me advice I trust?
SAM: Well, there’s Edd.
Jon gives Sam a look.
SAM: I’ll be more use to you as a Maester. More use to everyone now that Maester Aemon’s gone. The Citadel has the world’s greatest library. I’ll learn about history, strategy, healing. And other things. Things that will help when they come.
Jon stares at Sam, saying nothing.
SAM: If Gilly stays here then she’ll die. And the baby that she named after me will die. And I’ll end up dying, too, trying to protect them. Which means that the last thing that I’ll see in this world will be the look in her eyes when I fail them. (pause) I’d rather see a thousand White Walkers than see that.
Jon inhales, exhales, then nods somberly. Sam smiles.
Game of Thrones, Season 5 Episode 10, "Mother's Mercy"
Como você pode ver, Jon só concorda em enviar Sam depois que Sam explica que ele vai aprender coisas para ajudar, Jon estava relutante inicialmente.
Note que isso é verdade no episódio 5 da Season 7, "Eastwatch", quando Sam deixa a Citadel depois de saber que os meistries estão arrastando os calcanhares para ajudá-lo a se tornar um e depois de encontrar os livros que o ajudarão. A transcrição a seguir detalha que Sam pega livros antes de sair reforçando esse fato.
SAM is walking through a dark library. He heads to the restricted section and unlocks the barred gate. He begins removing books and scrolls from shelfs and stuff them in his satchel. After retrieving what he needs, SAM quickly walks to the exit of the library. He pauses before he leaves and turns around. He glances back at the library. It is many stories tall lined with countless shelves of books. SAMWELL looks at the library one last time, turns and walks out of the door.
CUT TO: EXT. CITADEL
SAMWELL is loading a wagon with his things. He walks around to the driver seat. GILLY and SAM JR. are already in the wagon dressed for the road. SAM climbs aboard and takes the reins in his hand.
GILLY: Are you sure you want to do this? You always wanted to be a maester.
SAMWELL: I'm tired of reading about the achievements of better men.
Game of Thrones, Season 7 Episode 5, "Eastwatch"
Note que Sam também já tem alguns livros úteis em sua posse e já enviou informações a Jon Snow sobre o paradeiro de Dragonglass em Dragonstone.