I was subject to fits of feeling myself unworthy.... It didn't take much to bring this sensation to life, along with the certainty that everybody but my mother saw through me and did not like what they saw.

Jack explains his chronic feelings of guilt and self-loathing in Part One, Chapter 2. Throughout Jack's childhood, he is plagued by this same feeling of unworthiness, convinced that he is guilty of or responsible for things he does not have control over, such as his father's abandonment of him and his mother's involvement with abusive men.