Yes. In a previous flashback/dream, his mother asks him to die for her. She was there when the fire started but was rescued, while he wasn't. He might not have agreed to be killed (unclear) but certainly he'd think that she set the fire to kill him and so he left. The person who did die in the fire might've been his half brother as his dad had other kids outside of marriage or it could've been someone else but he clearly feels responsible because the fire was set to kill him (he thought by his mom) and he didn't die. There's also a question about the mole under the eye, which has never been answered. That supposedly differentiated him from a similar looking half brother. We also have the monk/teacher who has immense wealth and travels secretly through the country. Many mysteries still to figure out, but at least we know for sure his mom didn't "kill" him.