It just means that if someone hates you, they still have feelings for you. If they really didn't care about you, they'd just forget about you. They wouldn't even waste the time hating you.
Barry LygaJazz hadn't given her many details of exactly what life in the Dent house had been like, but he'd told her enough that she knew it wasn't hearts and flowers. Well, except for the occasional heart cut from a chest. And the kind of flowers you send to funerals.
Barry Lyga