Talking with Terrell and Carl in their den yesterday, I thought of the old Crosby, Stills, Nash and Young song "Teach Your Children."

The song describes parents teaching children and children teaching parents. Terrell and Carl say they haven't just learned from each other; they've each been shaped by the other.

"I have learned how to be content from them," Carl said, referring to Terrell and his late daughter Dominique. "I learned how to make the best of my surroundings from them."

Before he learned that lesson, Carl, like many Americans, said he was always striving for better -- constantly trying to be the best at work and to have more material things. "I was never satisfied," he said. "I always wanted more."

He'd also complain about little things.

"My kids never complained. Not one day," despite living with sometimes-debilitating pain, he said. "Now I say: What would my kids do with this?"

Terrell, for his part, said he's learned from Carl "how to be a man for the family, to be a head of a household, how to keep things together even if things are difficult."

And Terrell has learned from both of his parents how to speak up for himself in medical settings -- to be an advocate for himself and make his own decisions.

Terrell said he's not bitter about his disease or his impending death.

"These are just the cards I was dealt, so I'll play the hand the best I can," he told me.

Carl said such words are the essence of the lesson his son is teaching him.

"To be dealt that hand and to have this outlook, it's amazing," he said. It's just amazing."