Sara was laughing about the opening to Game of Thrones. Tyrion Lannister, a dwarf, calls Jon Snow a bastard no fewer than four or five times in a single conversation. It’s pretty heavy-handed — it’s like Martin thinks we’ll forget — but it’s also the author tipping his hand a little. Several of the heroes in the book are “cripples, bastards, and broken things.” In fact, the majority of my favorite characters (and yours, right?) are “broken” in some way.
Bran Stark loses the use of his legs. Tyrion is a dwarf, an imp, a half-man. Jon Snow is a bastard. Hodor is mentally handicapped. Sandor “The Hound” Clegane is scarred with burns. Samwell Tarly is fat, disinherited, and a coward. And in Storm of Swords, even a villain or two gets taken down a peg along the way to becoming POV characters who are more readily sympathetic. (Spoiler: Jaime Lannister )
When travelling to the Wall, Tyrion says (more or less) to Jon Snow that because of his physical limitations, he’s been forced to consider other modes of strength. This ultimately becomes the take-away point of Game of Thrones — learning your limits makes you flexible and resourceful, which makes you stronger. As the world changes, those who are used to change will bend and adapt.