After having blown something insignificant out of proportion, a person may use the phrase "I'm over it" in an attempt to save face and maintain the guise of a seemingly laid back attitude. This may directly contradict a preceding statement.
In this particular example of "I'm over it", the subject is a towel which has been left hanging outside the laundry, awaiting the next load of washing.
Amy: "Can we do something that towel?"
Dan: "It has only been there a few days, I'll put it in with the next load of washing"
Amy: "Well you know how I feel about towels... I'm over towels!!!"