In what way might baba have seen Amir as having “stolen” from him

Baba explained to Amir that the only sin is stealing, whether a piece of property or a life. Baba knew about having things stolen firsthand; his father's life was stolen by a thief who stabbed him to death while robbing his house. Amir was grateful that Baba spoke to him so personally, but felt a simultaneous guilt for not being more like his father. He always felt that Baba hated him a little for 'killing' or "stealing" his mother as he was born.