Washington Irving first makes Rip an interesting character to us by treating him as a comic figure—a happy-go-lucky man whose children and farm are going to ruin while he is out fishing, helping a neighboring housewife with a minor chore, or hunting for squirrels. Irving also makes Rip a sympathetic character by telling the story from his point of view. From Rip's perspective, he has to escape as far from his household as possible as often as possible because his wife is a relentless shrew. She might have a different version of the story, but it is not one we hear.
Our interest in Rip increases as we follow him one day deep into a part of the Catskills that seems enchanted, filled with odd people in old-fashioned Dutch costumes who are bowling and drinking beer. We wonder what adventure Rip is going to have, but, he being Rip, we are not surprised when he goes to sleep.
Our interest increases, however, when he awakes and returns to the village, only to find out that he has been asleep for twenty years and everything—including himself—has changed. This piques our interest because it is relatable: we, too, might begin to wonder what we would do in Rip's shoes, suddenly twenty years older and having to cope with a whole new world.
Rip's happy-go-lucky but sympathetic character and his unusual adventures keep us interested in him.