The context of the following conversation is Remembering his traumatic past, Lee came into Quinn's head.:
Lee says I've been thinking a lot about Quinn lately..
The friend responds You two have been through a lot together..
Lee responds I've had some traumatic things happen to me in the past, and Quinn was usually there when it happened..
The friend responds I'm glad you two can get into each other's heads about it. Not everybody has such close friendships..
Lee responds I know. I'm really grateful..