First thing - I really, really, really hate Castiel's eye on this. But don't tell Castiel that, because first he will
1. Get mad
2. Talk to you in monosyllables.
3. Set a Leviathan on you.
4. Make a speech about setting an archangel on you.
5. Smite you.
6. Get pissed off at your ghost form.
Personal experience, don't ask how I know. Well, you can ask. It's not quite as literal a Castiel as you would expect. Anywho.
So the quote is from "The Man Who Would Be King" from Supernatural. Character is Castiel (obviously) who lost his wings, as a fallen angel type thing.
I don't own Supernatural or Misha Collins or Castiel (no matter how much I wish I do)