Gotham, Season 2

Bruce Wayne:
[in a letter to Alfred] Alfred, I have left home for awhile to live on the streets with Selina. Please, wait and listen before you react. You need not worry that I'm in danger or that I have lost my mind. I've thought long and hard about this decision, and I know it's the right one. Malone's death made me realize a couple of things. You can't kill murder. You can't get revenge on evil. You can only begin to fight such things by not doing them. You can only fight them where they live, not just at Wayne Enterprises. In the streets, in the slums, in the bad parts of town. So that's where I'm going.

Alfred Pennyworth:
He's lost his mind.

Bruce Wayne:
I'm not going to start battling muggers or anything, but one day I am going to do something to help the people of Gotham. I don't know what yet, but I will. Meantime, I need to learn stuff. Number one, I need to learn how to live in the same world other people have to live in. Selina's given me a place to sleep, and will show me the ropes. So, like I say, there's no need to worry. I'll be in touch soon, and I'll come home eventually. Please, Alfred, trust me and honor my wishes. Don't try to bring me back. I need to do this. Sincerely, your good friend, Bruce.