Who missed the end statement about dying a good man?
Spoiler alert.
Di Capprio's character faked his final madness in order to have a lobomoty and so 'die a good man', rather than 'live like a monster', as he said, knowing his past. It's a very good and subtle ending.
This alludes also perhaps to how many schizophrenic patients commit suicide (around 10%), they cant live with either themselves, or their madness, in many cases.