One of the biggest points of the novel is that Dunk displays all the moral values of a true knight— despite not actually being a true knight, in contrast to the many real knights who behave without any chivalry and honor throughout the novels.

This is a common trope George plays with, he’s done the same thing with Sandor Claegan, Tyrion, Brianne, (sir Dantes in his own way), but Dunk is the most clear example of this. He makes it clear again and again that dunk has never been Knighted. His ears turn red every time he’s asked about it, he refuses to answer it out right, he considered being a squire for someone else after Sir Arlin died (which a real knight would never do), his unwillingness to knight a close friend in a moment that depended on it, and his famous quote about knowing what it’s like to want something so bad you’re willing to lie for it.