What is the author's tone in The End of the World as We Know It: Scenes from a Life by Robert Goolrick?

Goolrick's tone varies throughout. Sometimes, his tone can be combative, as he describes arguments and emotional outbursts with loved ones in the throws of alcoholism and abuse. At other times, his tone is intimate, as though he is passing secrets between friends. Always informal, Goolrick's tone changes during different parts of his story for clear reasons. When he discusses his parents, his tone is not only aggressive and combative, but also sarcastic. When discussing his own shortcomings, Goolrick's tone changes to somber and depressive, with undertones of self-hatred. When speaking of those he does love, such as his siblings and his other relatives, his tone is endearing and even playful at times.