You should use the word "I" when it is the subject of a sentence, and the word "me" when it is the object of a sentence or of a preposition. "I want you to understand me." "I want you to listen to me."
Knowing how to use a word in a sentence is very important in learning the word meaning. A sentence with the word absence is;Their mother's absence , had the children worried, they had not seen her all day."