It gets the lesson properly started when Harry learns he was given a Guardian potion with Sirius the day he was born, a Potter tradition when naming godparents, and the fact that brewing the potion and administering it to an infant is stupidly illegal. "They could have been in serious trouble if anyone had reported them because the potion requires blood from both parties, including one that couldn’t consent -- you. Yet these potions are extremely common in well-established families to give a blood-bond between a chosen Guardian and a child just in case."