Mary Barra, CEO of General Motors., excites us with plans to build a flagship Cadillac sedan at GM’s Detroit-Hamtramck plant. Gilbert and his investor pal Warren Buffett yuk it up on stage. The city’s hockey prince, Chris Illitch, gives us a peek at the new arena blueprints. When I bump into Ilitch later, he says the city’s political and business leaders have not been this united in 50 years–and I believe him.

It’s all so impressive, this conference, and yet … well, this is still Detroit. Barra doesn’t bother telling us that she’s moving GM’s Cadillac brand to New York, of all damn places. Buffett laughs off Gilbert’s attempt to secure investment commitments. Duggan has no good answer for the fate of Detroit’s schools.

It’s up to the event’s keynoter, Dan Doctoroff, to bring us back to earth, to acknowledge the gulf between hope and reality in Detroit. A hometown boy, Doctoroff served for six years as New York City’s deputy mayor. He’s the conference’s realist, telling the expats to temper their aspirations. “The goodwill money runs out quickly,” he says, adding that smart money won’t come until investors see population growth.

Doctoroff predicts that journalists eventually will grow tired of writing “Detroit comeback” stories and shift to “Detroit missed its opportunity.” He urges city boosters and leaders to “think small.” Rather than overpromise, do the little things well, he says, and create a “virtuous cycle” of success. Fix the street lights. Repair the roads. Pick up the trash. If one person notices that the city trash service is picking up garbage on schedule, after years of mismanagement, that person might start putting his trash out on time. A neighbor might notice and start dragging her trash to the curb on time, too. One day, Doctoroff says, a suburbanite might drive through that neighborhood, notice how clean it’s become, and buy a home.