It's the thing that keeps him focused and prevents his lapsing into depression or pity.
Andy tells his friend, "Remember, Red, hope is a good thing, maybe the best of things, and no good thing ever dies." You're never a prisoner if you keep hoping for the future. He maintains an inner sanctuary for what life is supposed to be, evidenced in scenes like the one where he’s put in solitary confinement.
Political activism against the Chinese government had earned Chen six years of what he called “brutal” detainment—translation: regular beatings—first in prison and later under house arrest.
And so, to escape, the 40-year-old Chen waited for a moonless sky, and then scaled the government-built wall around his house, relying on his other senses to guide him across rivers and roads.
"Some birds are not meant to be caged," Red reflects.
Andy also finds ways to embody hope throughout the film in small physical manifestations that remind imprisoned people what it's like to be free: a bottle of beer, a funded library, some money and a note left under a tree.
Although the film adaptation shortens the title, Rita Hayworth remains a powerful symbol within the film, representing the beauty of hope.
25 years is a long time to chisel away at a prison wall using a tool hardly bigger than a fork, but it's a hobby that keeps Andy sane.
Three hundred miles later—at one point he was reduced to crawling after breaking bones in his foot—the fugitive reached his sanctuary: the American Embassy in Beijing..
The embarrassed country’s Internet police tried to squelch the story by censoring micro-blogs, an information-sharing platform in China similar to the government-banned Twitter.