"Well..." he began. He was acting nice? Was this just not simply courteousness that everybody was supposed to show? Then it finally hit him: His manners were all towards other nobles. Until recently, when he began traveling out to the lower-class part of town, he had never once interacted with someone who had lived there. So, he simply assumed that he was to speak to everyone with the same amount of respect. "... do I have some reason to act any other way?" he questioned.
It might be quite possible that his confinement to the castle until recently may have backfired if the King expected him to have similar views towards the peasants. That, and Jacob interprets some things quite differently. Whereas one person may have become even more spoiled being confined to a life of nothing but luxury, Jacob ended up feeling upset for those who did not know even the most basic (his opinion of basic is a bit messed up due to his confinement) luxuries. Maybe anybody else would be even more prejudiced against the less fortunate because they experienced absolutely NOTHING about them, Jacob simply tried imagined living without everything he had and it scared him. This is what led him to believe he needed to become a king who ASSISTED the people, not USE them.
"Though I do believe most of my fellow upper-classmen have the idea that being born into a wealthy family gives you the right to flaunt coin you have not earned by your own hard work. I can understand if you were expecting me to have such an arrogant viewpoint, but I am glad to say that I do not."