How in the world could Remus Lupin ever forget to drink his Wolfsbane Potion? Like, seriously, he's been a werewolf for practically his whole life. That's not something you just forget, right? What's wrong with him?
Even Draco’s parents couldn’t save him from becoming a death eater. People need to know the difference between a spoiled brat and an evil person. Draco couldn’t even switch sides because Voldemort was.