Stubborn Is As Stubborn Does
Optimism is supposed to die the second you're driven through the gate into Shawshank Prison. "Abandon all hope ye who enter here" might as well be engraved on a signpost. Everyone other than Andy Dufresne seems to get it. They're more or less living, breathing zombies (which sort of goes against the whole idea of being a zombie, but stay with us) who have given up on life as they once knew it; they have accepted their fates as "institutionalized" individuals who will never again see the light of day. Not until they're old men, anyway.
However, Andy's a whole different animal who's lived a different life than most of the men. He doesn't escape the ugliness of Shawshank any more than his fellow inmates, but instead of letting certain events break him, he uses them as motivation to fuel his escape. Knowing it will take twenty years to tunnel through the prison wall should seem so daunting that a person's discouraged from even trying it, but not so for stubborn ol' Andy. What Red views as an impossible task, Andy sees as worth attempting.
ANDY: No, here's where it makes the most sense. You need it so you don't forget.
ANDY: That there are places in the world that aren't made out of stone. That there's... there's somethin' inside that they can't get to; that they can't touch. It's yours.
RED: What are you talkin' about?
Some people may view that kind of stubbornness as infuriating, but sometimes, when thrown into difficult circumstances, it can be the only way to get things done, as Andy shows. Be infuriated all you want, inmates of Shawshank Prison. You're in there and he's out here. To be fair, as an educated professional man, he was probably used to feeling that he could get things done if he wanted to. He lived a life of privilege compared to most of the inmates. After he left, they talked in amazement about his chutzpah. He gave them hope—maybe not hope that they could escape, too, but hope that they could live in the system without it destroying them.
Secrets, Secrets, are No Fun…
A big part of the reason that Andy's escape is successful is that he trusted no one. Probably not a great life lesson to take from him in that regard.
Even Red, his best friend in the world, never knew a thing about his plans to hightail it out of there. The reason for this was probably two-fold. For one thing, the less Red knew the less he could be held accountable for assisting Andy, so in a sense he was protecting him. Perhaps more importantly, Andy had put far too much time and effort into pulling this thing off to unnecessarily entrust a secret of that magnitude to anyone else. He probably trusted that Red wouldn't rat him out to the guards, but even the slightest little slip to one of the other inmates could bring the whole grand plan crashing down.
Also, we get the sense that Andy didn't suddenly develop the secretive gene once he got to prison. What we know of the type of husband he was, and how he behaved in his court trial, leads us to believe that he was never a real "wears his heart on his sleeve", "open book" kinda guy. His emotional distance led to the demise of his marriage but it also likely gave Andy a leg up in the slammer. He plays his cards close to his chest. Okay, enough already with the clichés.
We have to think he was also trusted with all of the juicy, Shawshank gossip. You know, who's planning on stabbing who in the prison yard, etc.
ANDY: On the outside, I was an honest man. Straight as an arrow. I had to come to prison to be a crook.
Where's Alanis Morisette to sing a few bars of Ironic when you need her? Yeah, Andy's life has had quite the unusual trajectory. While he may have his regrets, he wasn't guilty of the crime for which he was convicted, so he never deserved to spend any time inside a prison.
However, once he got there, the rules changed. Look at the stuff the inmates have to do in order to get by: gamble on the frailty of newcomers to earn cigarettes, which in prison are a form of currency; smuggle goods in through the laundry; resort to violence in order to defend themselves from physical attacks, and, in Andy's case, help the warden launder his dirty money so he can stay in the big guy's good graces. Suddenly, everything that would be frowned upon in the real world is just status quo at Shawshank Prison.
Stranger still, Andy doesn't seem to feel any compunction about his moral transformation. Because he used to be so straight-laced, if he ever had committed theft or seriously hurt someone in his former life he probably would have been overcome with guilt. Remember, though, Andy's playing the long game. He's probably figured out long ago that he can use his knowledge of the warden's crooked schemes to his own advantage some day.
While he may have gotten a little more flexible with his principles, Andy hasn't gone completely over the ledge. He doesn't steal from his fellow inmates. He doesn't go on any killing sprees. He simply uses his newfound talent for criminality to target those who deserve it. Now that's a criminal we can root for.
He's Mad as Hell, and He's Not Going to Take This Anymore
Andy's able to maintain his cool, calm demeanor through basically the entire film until he has a chat with Red late in the movie and seems to get pretty frustrated. This is right before he makes his escape. The tunnel is finished and everything. If he's finally about to see everything he's worked toward come to fruition, why are his undies in such a bunch?
Clearly he's not frustrated about being stuck in Shawshank, since he knows he's going to be able to get out of there. What is getting his goat is some serious inner turmoil.
ANDY: I didn't pull the trigger. But I drove her away. That's why she died. Because of me, the way I am.
RED: That don't make you a murderer. Bad husband, maybe.
RED: Feel bad about it if you want. But you didn't pull the trigger.
ANDY: No. I didn't. Someone else did, and I wound up here. Bad luck, I guess.
RED: Bad luck? Jesus.
ANDY: It floats around. Has to land on somebody. Say a storm comes through. Some folks sit in their living rooms and enjoy the rain. The house next door gets torn out of the ground and smashed flat. It was my turn, that's all. I was in the path of the tornado. I just had no idea the storm would go on as long as it has. (glances to him) Think you'll ever get out of here?
For one thing, Andy's probably been repressing a lot of emotions that any qualified psychiatrist probably would have advised against doing. In order to stay sane, he's pushed some feelings down below, so he can avoid distractions and stay focused on his endgame. Now that all that's done, stuff is finally bubbling to the surface.
Not just about his unfair punishment. Andy talks here about what a crappy husband he was, and that he blames himself for his wife's death, even if he didn't pull the trigger. If Andy emerging from the sewer and being deluged with raindrops represents the cleansing of his soul, then this is his moment of confession. He's getting things off his chest so he can purge the blame he's placed on his own shoulders, clear his conscience, and prepare to start life anew. Albeit with wet socks.
Andy's also probably frustrated that, while he may be getting out, he won't be able to take his good friend with him. He doesn't even feel comfortable giving Red a heads-up about what he plans to do, since having any information on Andy's escape could only get Red some time in The Hole.
As great personal triumphs go, Andy's got some mixed feelings. Fingers crossed that sticking it to the warden made him feel a little better about the whole thing.