"I spent more time with my on-screen mother (Catelyn Stark, played by Michelle Fairley) and my on-screen friends than my own friends — so this is your family," he said.
"But I was ready to go. I knew that I'd be leaving the show at the end of season three."
He continued: "That's five years of your life. Which is another interesting thing as an actor; how long is too long to be playing a part? I'm looking at some of my friends who are ten years in there, and I'm going 'wow... you've really changed over the show and [have grown as an actor'."
"I was ready to kind of say goodbye after three seasons and say 'thank you, have a brilliant death and I'll go and explore other things'."
Indeed Robb did have a brilliantly brutal and unexpected death in one of — if not the — most shocking moments of the show, when he was betrayed and murdered (along with his direwolf, wife, unborn son and countless bannermen) at his uncle's wedding at the the hands of the treacherous Boltons and Freys.
Catelyn too was killed at the scarlet ceremony in season three; however some fans believe she may return as Lady Stoneheart in Sunday's upcoming episode.
With the Night King laying siege to Winterfell, the defending forces have sent the women and children into the crypts where all the Starks are buried — perhaps not the safest place considering their opponent has the ability to raise the dead.
While Madden's Rob could be interred down there too and theoretically could just as likely make a zombie cameo on Sunday night, Lady Stoneheart is an actual character from the source novels, "A Song Of Ice And Fire".
Madden meanwhile did go explore other things; his lead turn in BBC's Bodyguard earned rave reviews, while fans were gutted when he shot down rumors he would play the next James Bond.