Dill had it all, anything that he wished upon he received except for parents to stay togethet. He felt that his parents don't spend any time with him ever since his mother remarried. He didn't feel like they needed him anymore even though he needed them.
To build motivation for the character gives a backbone to the story and about the Arthur for example if the Arthur got the motivation from seeing a kid take a candy out of a store that motivation for that character would be a bad guy or a heel and or antagonist there for the motivation for a character is very important they reveal it so you can get a bit of a background on the character in more information on the story and the Arthur.
I definitely can't answer for your personality lol<span />