CHICAGO (CBS) — Legendary football coach Marv Levy knows all about getting close but never winning the big championship, so when his beloved Cubs finally ended 108 years of frustration, the 91-year-old Chicagoan wrote a book about their historic World Series win.

Levy led the Buffalo Bills to four consecutive Super Bowls, but they lost all four. The Hall of Famer is a World War II veteran, has a master’s degree from Harvard, and now he’s a children’s book author.

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“That, I did not ever think would happen,” he said. “I had written some books … and the publisher called me, because they knew I had been a lifelong Cubs fan; asked me to write the text for this children’s book, and it was a delight.”

“I don’t have any words too big for even me to understand,” he joked about his latest book.

Pro Football Hall of Fame coach Marv Levy reads from his new children's book, "Go Cubs Go," about the Cubs' 2016 World Series win. (Credit: CBS)

Pro Football Hall of Fame coach Marv Levy reads from his new children’s book, “Go Cubs Go,” about the Cubs’ 2016 World Series win. (Credit: CBS)

Levy gained a passion for writing from his mother. He wrote a best-selling autobiography and penned three other books.

His latest, “Go Cubs Go,” tells the story of a bear named Bruno as he follows the team from 1929 right up to Game 7 of the 2016 World Series.

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Levy, a South Sider, was at the Cubs’ last heartbreaking World Series in 1945.

“I can remember walking out after that seventh game, which I was able to see,” he said. “I was home on furlough. The war, World War II, had just ended, was able to get a ticket. It cost a whopping $1.10, by the way, but I remember walking out with all other Cub fans who felt badly. They didn’t win the World Series, and the chant began, ‘Wait ‘til next year.’ Well, that’s what we’ve been saying, or had been saying for 71 years.”

Levy has two grandchildren and hopes they can take something away from his book.

“Just that sports is fun,” he said. “Celebrate when you win. If you don’t, go back to work. Never give up. That is the message.”

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Levy’s grandchildren were among the first to read his book and they gave it a big thumbs up.