You know what you didn't die today? Because you didn't know the ...
Peter: You know what you didn't die today? Because you didn't know the protocol. If you stopped for oxygen you'd be dead right now. But you did something he couldn't factor in, you kept running. You know why you did that. It's the same reason you thought you saw Walter in that hospital. It's the same reason you think you are seeing me now. You're not from this world Olivia. You're not her.
Olivia: You're not real.
Peter: Real is just a matter of perception. I am here and I'm a part of you, that you have to hold on to. You can't forget who you are Olivia. You can't forget where you're from.