I think Wilbur can be kind of self-centered and selfish. Having Fern around, nursing him all the time, got Wilbur to become one spoiled little pig. Fern would always feed Wilbur, and put him to sleep. Being forced to live in a barn with other farm animals, must have been a challenge. There, he wouldn't have a Fern that would care for him like a little baby.
Charlotte, the spider, was very welcoming and nice. She dazzled Wilbur with her beauty, and impressed him with her wisdom. They become good friends though, and trusted each other, always. Charlotte was always helping Wilbur in any way she could. She was small in size, but could do big things. Once Wilbur finally learned that he was supposed to die, Charlotte had a plan. She took care of everything. And in Wilbur's mind, Charlotte was the new Fern.
Wilbur is constantly thinking about himself. He complains about his life style, and how he's living in a small barn. But yet, Charlotte doesn't get fed by someone everyday. Charlotte must rely on careless flies to land on her web for every one of her meals.
Charlotte had done so much for Wilbur. She saved his life, has been a good friend to him, and guided him. And now, I find my self asking what has Wilbur done for Charlotte in return. This situation is very similar when it comes to borrowing money from friends. When you borrow money from a friend, they expect you to pay it back as soon as you can. Wilbur got the help he needed to stay a living pig, and he would still expect more. Fortunately, Wilbur watched over Charlotte's children and grandchildren after she had died. Wilbur was so lucky to have such a friend. I'm glad he finally returned the favor.