On HBO's Game of Thrones, not many characters survive one season of machinations, much less six. Frankly, people, giants, dire wolves and even kids drop like flies on the show, just like world-builder/creator George R. R. Martin likes it. So for actor John Bradley's Samwell Tarly to be alive and thriving as Season 7 debuts tonight is truly something special.

When last we saw Tarly and his lover, Gilly (Hannah Murray), and his adopted son, Little Sam, the trio had finally made it to the fabled repository of knowledge, the Citadel, where Samwell intends to become a full Maester and help Jon Snow fight the impending, dire threat of the White Walkers in the North.

From London, Bradley got on the phone with us to talk about not only his character's growth on the series, but also Bradley's seven years of personal learning from the best of the best behind, and in front of, the cameras on Game of Thrones.

John, you were fresh out of drama school when you landed the Samwell Tarly role. So there was no slow roll into your career. Was there any negative to that?

Yes. All of those things an actor dreams of fell into my lap the second I started acting. It was my first job, and I've been doing Game of Thrones ever since. The one conflict for me for the last few years is that one of hardest parts about acting is meeting new people all the time, and finding your rhythm and place, and making friends. I've had to do that on other jobs, but always with the security that in the second half of the year, I'm going to be back in that same old family unit with all those familiar faces, and it's like going home. And now we all know our characters well enough, especially people who have been on it since Season 1, like myself, that we can slip into that skin pretty quickly now and establish contact with the character in quite an efficient way.

Did you feel a lot of pressure walking onto a project the scale of Game of Thrones as a young actor?

It's not negative pressure. I've always thought pressure is a real privilege. And working with a crew this size, and a cast this size, which is huge and expansive with all incredible actors, you just want to make sure your patch on that quilt is as strong as everyone else's. You do the scenes and you see the work that's gone into the set, and the work done by the camera department, and the art department, and it inspires you to work as well as you possibly can. You don't want there to be a dropoff between scenes, and the one that lets down the quality. But you also know the producers and directors think you are capable of doing it, so you feel incredibly flattered.

Did the rest of your cast help you find your bearings?

What was great about the first few seasons is that I was working with a lot of other young actors for whom this was their first big job as well. You find yourself working with others who aren't as sure, and felt we were out of our depth and could lean on each other. I, of course, felt supported as well by the group of more experienced actors at Castle Black like Owen Teale (as Alliser Thorne), James Cosmo (as Jeor Mormont), Peter Vaughan (as Maester Aemon) and all these people. It was a very nice mix of students and masters. Peter Vaughan is still very popular in this country from a sitcom he did in the '70s called Porridge. I grew up a huge fan of it, and when I found out I would be working with Harry Grout of Porridge, I was so excited. It was like someone stepping out of my childhood. It was big boy stuff, so I felt like everything had been leading up to that. Then I worked with him and found out he'd gone head-to-head with Frank Sinatra in a movie in the late '60s. It was serious big boy stuff! He's not with us anymore, but I'm sure working with me was a downward slope. (Laughs) But everyone was supportive and kind and patient with us.

When did you really figure out what Samwell's function in the story was?

I think by the time we got to Season 4, in Episode 9, "The Watchers on the Wall," with the attack on Castle Black, I think that's when my function in the story really came into clarity. We're dealing with a situation where a group of men have to fight against all odds, against 9-foot giants and a whole bunch of cutthroat Wildlings who want to tear them from limb to limb. Characters like Jon Snow are the strength and the ideal and can deal with that. He chops people in half and has the skills to be the hero. But in order for those stakes to really be heightened to the nth degree, and for all of that to really matter, and for the danger to be put across in the most effective way possible, you need to have a character in there who is scared and who can't handle it. If everyone was like Jon Snow, the threat of the Wildlings would be severely compromised, because everyone could deal with them. You need Sam in there to benchmark the ordinary, scared guy who can't face what he needs to face. You need that to establish Jon Snow as something braver than that.

In Season 6, Samwell got his own standout episode when he went back to his home with Gilly in "Blood of My Blood." The audience got to meet his awful family and finally get to see Sam become his own man. What did that moment and episode mean for you, and the character?

That was definitely the sequence that I wanted to happen ever since I started working on the show. When we first meet Sam, he mentions his father in that very first scene. And then later on in the episode he starts talking about all the psychological abuse that's been inflicted on him, and how damaged he is. He carries a lot of scars around with him. They don't show, but he's broken inside. And then over the course of the next few seasons you see Sam changing. People ask me the question of what Sam has learned over the course of those six seasons, and I'm tempted to say he didn't learn anything. What he did was unlearn things. It's not so much that he acquired new skills and he understands them, but he stripped anything that wasn't true about himself. Everything the audience could see about Sam that was true that he couldn't see. What you find is Sam shedding all of that baggage. You see him shedding it away layer by layer and finding out how unique and worthwhile he is. You see how he starts Season 6 and he's come such a long way. There are flashes of the bravery, and the instincts and the impulse to do good. So you want him to go into Horn Hill and walk up to his dad and say, "You have to treat me with respect now. I've changed and I don't believe all that stuff you've said about me anymore. I've come back to show you what I've become and I'm sorry I ever listened to you, because everything you said about me is wrong." On the flip side, he could have gone home and instantly regressed to the boy he was before he left. You don't know where it's going to go.

Was stealing the sword and leaving his family behind a beginning or an end?

In the end, it's a satisfying mixture of the two. When he sat around the table in the withering glare of his father, he does revert and start to shrink back into himself. He's feeling worthless, but Gilly spots that and that's why she stands up to him. In his head, he takes that sword because he has to conquer that side of him again. He has to get back in touch with that scared boy to finally realize he's changed, and not that anymore. He takes it as a final act of defiance. I thought it was really emotional. It was the shedding of the final layer of self-doubt and uncertainty. It's the very last remnant of all of that psychological damage.

What is the Citadel going to mean for Sam and his future?

Sam arrives at The Citadel and for the first time in his life he's where he feels he belongs. He's surrounded by people who can share learning, knowledge and academia. He's never had that before. He's constantly been told that's a waste of time, and he's not going to affect the world unless can wield a sword. Now he is in a place where people don't believe that. And if you think about his level of achievement in surviving Castle Black, and he's so geographically far away from that, and you wonder where this guy's happiness is going to come from. But against all odds, he falls in love and takes on the mantle of parenthood, and that gives him a reason to stay alive and a purpose. The last few seasons has been him manipulating his way to The Citadel, which is where he can do his bit. He doesn't want to go there for a comfortable life, to put his feet up and read. He wants to go there because that's where he feels he can fight the same battle as everyone else, but he knows there are any number of men who can wield a sword or axe. But he's the only one who can bring something else to all of this. Whether The Citadel will match this idealized idea that he has of it in his head is another matter altogether.

Was shooting Season 7, and knowing you all are going back for the final chapter this year, more bittersweet?

Yeah, it's a combination of emotions. It's bittersweet letting go of a job you enjoy doing very much and working with people you love, respect and really admire. When it comes to that sense of the show coming to an end, you really did feel a sense of momentum gathering shooting Season 7. Even though we shoot with two units all the time, so there are always two scenes being shot on any one day, and even though the scenes I do involve talking, exposition and character, which are more low-key scenes, you did get the impression there was big stuff being shot all the time. And there were big set pieces being shot every week, where there are hundreds of extras around and all of this technical equipment, so big stuff was happening at a more alarming rate than ever. They're doing seven episodes now [per season], but people shouldn't feel short-changed. What they're going to find is 10 episodes of drama packed into seven very rich episodes.

Sam's doing pretty well, but do you think it's possible for anyone to have a happy ending in this dark world?

The funny thing about that is that everybody on the show is on a quest for something, whether it's the Iron Throne or a land. It's all about power, and they won't be happy until they have that power. But with Sam his expectations are so modest. He doesn't want the Iron Throne, as good as it would be for everybody. He just wants to have an effect. He wants to fight a battle, be loved and love somebody. It's another reason he's an everyman. He doesn't want the extremes that other people want. He just has modest wants. Interesting thing is when we first arrived in the series, it was as impossible a goal to him as the Iron Throne was to everyone else. But just finding out who he is, he's managed to achieve most of that, so a happy ending for him is a happy ending for most people watching in 2017, and that's why he's such a relatable character.

Any other of your roles we should look out for this year?

I did a really intriguing movie last year called American Satan, which is an updating of the Faustian legend about a guy who sells his soul for rewards. It's a modern-day, rock-and-roll updating of it. There's a bunch of guys from bands, and Malcolm McDowell plays the devil. It's very, very interesting.

Video of Game of Thrones Season 7: #WinterIsHere Trailer #2 (HBO)

Game of Thrones Season 7 returns tonight, Sunday, July 16, at 9 p.m. ET on HBO.