I believe that parents who love and sacrifice for their children cast a spell on them, so to speak. Though those children may disobey and rebel, once they leave home their parents' words will haunt them. When faced with challenges and responsibilities, their first - almost reflexive response - will be almost exactly as their parents' (whether good or bad). Those children may spend years and years sorting through what they have received through their parents' "spell," versus what they choose for themselves.
I'm sure this is not the case with all families, but it's been true for my relationship with my parents. I'm thankful for what my parents taught me, as much by their example as by the words they spoke. They weren't perfect, but they truly loved me and sacrificed much for me.