Morty: Hey, uh, y-you doing okay? I kind of know how you feel, Summer.
Summer: No, you don't. You're the little brother. You're not the cause of your parents' misery. You're just a symptom of it.
Morty: Can I show you something?
Summer: Morty, no offense, but a drawing of me you made when you were eight isn't gonna make me feel like less of an accident.
Morty: That, out there? That's my grave.
Summer: Wait, what?
Morty: On one of our adventures, Rick and I basically destroyed the whole world, so we bailed on that reality and we came to this one. Because in this one, the world wasn't destroyed. And in this one, we were dead. So we came here, a-a-and we buried ourselves, and we took their place. And every morning, Summer, I eat breakfast 20 yards away from my own rotting corpse.
Summer: So, you're not my brother?
Morty: I'm better than your brother. I'm a version of your brother you can trust when he says 'don't run'. Nobody exists on purpose, nobody belongs anywhere, everybody's gonna die. Come watch TV.
Rick and Morty S01E08