"I made him a promise." Kevin dragged his stare away from Nei..." — Nora Sakavic quote meaning

I made him a promise." Kevin dragged his stare away from Neil's face to follow Andrew's progress. "He's waiting to see if I can keep it." "I don't understand." Kevin said nothing for so long Neil almost gave up waiting for an answer. Finally he explained, "Andrew on his drugs is useless, but Andrew off his drugs is worse. His high school counselor saw the difference between his junior and senior years and swore this medicine saved his life. A sober Andrew is…" Kevin thought for a moment, trying to remember her exact words, and crooked his fingers at Neil as he quoted, "destructive and joyless. "Andrew has neither purpose nor ambition," Kevin said. "I was the first person who ever looked at Andrew and told him he was worth something. When he comes off these drugs and has nothing else to hold him up I will give him something to build his life around." "He agreed to this?" Neil asked. "But he's fighting you every step of the way. Why?" "When I first said you would be Court, why were you upset with me?" "Because I knew it'd never happen," Neil said, "but I wanted it anyway." Kevin said nothing. Neil waited, then realized he'd answered his own question.