KidStein said:
Not all Knights are noble-born. And if you're not noble-born, you most likely weren't raised and trained to be a knight. And yes, Sandor was not a knight. But only because he refused knighthood. And on average, the Knights of Westeros couldn't compare to Sandor, Jaime, Barristan etc etc.
Many good fighters aren't knights, while others are knights and fight like a child with a f***ing cheeseknife. Bronn wasn't a knight for a long time (until the Battle of the Blackwater) but he killed many knights.
You are not going to be a Knight just by raise in the most cases. Of course, it could happen (Bronn), but as a Knight you need lands, people and a lot of money. A guy raised to a knight just because he is a good fighter, has nothing in common with a real knight except of the name. Real knights are knights because they where raised for this job. A knight isn't equal with a good fighter of course, there are such things as housholdknights, siting around at court und attenting the king and such things.