Three words -"Brooks Was Here". He is an old man devastated by the news of his parole after nearly 50 years' imprisonment, who resorts to attacking Heywood to prevent his imminent release, breaking down into tears when stopped. Once he's a free man, he's overwhelmed by modern life, especially cars, and barely able to keep up at his convenience store job due to his ailing hands and unsympathetic customers. He has nightmares every night, because he is so institutionalized that he is completely out of place in this brave new world. He decides not to stay.
Red's words also hurt.
He should've died in here.
Andy's "Get busy living" speech and his conversation with Red that ensues as Andy desperately clings to his last happy memory and his only dream for the future while Red reflects on just how worthless his life will be once he does get out and how hope is just a "shitty pipe dream". The music does not help. Like at all. Of course this all gets completely turned on its head later but still....
After trying his hardest to get his High School diploma so he wouldn't be a complete waste in life, having a young wife and kid, and then succeeding at getting it and willing to help out Andy, Tommy's death being ordered by the Warden came as an immense and tragic shock.