A Knight Of The Seven Kingdoms Is Already Setting Up Its Central Mystery
The difference is knight and day.

A Knight of the Seven Kingdoms sets itself apart from other Game of Thrones shows in the first few minutes with the inclusion of cutaway gags: abrupt cuts to scenes past that add a punchline to a line of dialogue. When eulogizing the recently passed Ser Arlan of Pennytree, Dunk mentions how he never beat him when he didn’t deserve it, only for the scene to cut to a quick-fire montage of all the times when, presumedly, he did deserve it.
This willingness to look back is one of this show’s greatest strengths, but it does highlight one thing missing from these cutaways: the most important moment in Ser Duncan the Tall’s life.
Warning! Spoilers for Knight of the Seven Kingdoms Episode 1, “The Hedge Knight,” ahead!
We don’t actually know if Ser Arlan Pennytree knighted his squire before his passing.
While we see plenty of Ser Arlan Pennytree in this series premiere, we never actually see him dub his squire a knight. When Dunk speaks to the Games Master in Ashford, the action cuts away not to the knighting but instead to a young Dunk asking Arlan if he thinks he’ll ever become a knight, and Ser Arlan just spitting his food out on the side of the road as a response. When the Games Master asks if there were any witnesses to the knighting, Dunk just says a bird was nearby.
So there weren’t any witnesses, Ser Arlan never indicated a desire to knight Dunk, and a show full of cutaways and flashbacks never cuts away to this moment. This begs the question, was Ser Dunk knighted at all? We know he takes matters of honor and ceremony very seriously, but could he be lying to everyone?
Ser Duncan states his case before the Games Master.
Now that he’s among other knights and, crucially, has a squire of his own, we may learn about his backstory, but even if he wasn’t officially dubbed, that doesn’t make him any less of an honorable man. Maybe it’s not the oath that makes the knight, but the honor. And if the only way to gain access to be that honorable man is to tell a little white lie, then does it really still count as dishonesty?
Dunk may or may not have been knighted by Ser Arlan, but it’s very clear that he deserves to be in Ashford fighting with everyone else. In fact, he might just be more deserving than many who merely inherited their titles.