Quote from Lily in The Platinum Rule
Lily: Every time we step out the door, they're out there waiting for us. Sometimes, we'll send Ted out first as a scout. Nobody's there. Then we'll go out one second later, and there they are. Marshall: It's freakin' supernatural. Are they ghosts? Can only we see them? Lily: "Hey, neighbor!" "Hey, neighbor""Hey, neighbor." [bangs head on table] Barney: I remember that.