The opening of the novel presents a picture of Gulliver as a somewhat arrogant man with incredibly high expectations. His outrage at the changes made by the publisher without his approval is only amplified by his disappointment that his description of the Houyhnhms has not fundamentally changed society to something better.
This arrogance is only encouraged when he is among the Lilliputians as he is a giant and has incredible power for good or evil as he is among them. His confidence in his own power is somewhat mitigated by his frustration and disappointment in the society of the Lilliputians but his arrogance is still rather apparent.
In Book II, suddenly he is suddenly helpless and small amidst the Brobdingnagians, a circumstance that helps to remind him of his frailty. Though he is still cynical and critical about the society and government of the Brobdingnagians, serving to satirize specific elements of both the Tory and Whig conflict and other English affairs at the time, he becomes more aware of his own condition and this tempers his arrogance severely.