<p>One publisher after another told Mo Willems that a talking pigeon determined to drive a bus was an “unusual” idea, but not one for them.</p><p>“It really was spaghetti on the wall; nobody expected much of it at all,” said Willems, speaking to the Chicago Sun-Times earlier this month from his home in New York.</p><p>Two decades-plus and millions of delighted children (and adults) later, Willems has a new picture-book adventure featuring the world’s most famous pigeon: “It’s My Bird-Day!”</p><p>Has pigeon learned anything during the last 23 years?</p><p>“Barely,” Willems said. “The pigeon is becoming a bit more self aware. The pigeon has made discoveries, like its first name is ‘The.’”</p><p>Willems, 58, will be in Chicago later this year to accept the Chicago Public Library Foundation’s Carl Sandburg Literary Award.