Different, but the same

He sat on the sand, the cold, wet sand, watching a boy dance in the breaking surf. And though he'd known this boy, his son, for 10 years, it was as though he was watching a stranger.
Maybe because, as of late, they had been strangers.
And while the boy pranced in the sand, turning cartwheels and running from the encroaching surf, he thought about how little he really knew the boy. How could his son, so serious, be so playful? How could the boy, so self-absorbed and selfish, find joy in something as simple -- and free -- as running on the beach of the Marin Headlands.
They shared likes and dislikes. They battled and laughed. They were genetically linked.
But something had been unplugged recently. The boy had grown angry with his father. The father disillusioned with the angry youth.
It hadn't always been that way. Or had it?