That left Albus’ mother to raise himself, Ariana, and his younger brother Aberforth, and Albus rarely ever spoke of his family to anyone. After graduation, on the evening that he was all set to embark on a tour of the world, Albus’ mother was accidentally killed by Ariana, and he was forced to return home to raise his siblings. Albus was bitter and full of resentment for his situation, which paved the way for some difficult times in his life. We have no idea how Credence, revealed to be related to Albus in Crimes of Grindelwald, factors into all this.