I can tell from the way he puts the empty potato-chip bag down beside him that he's going to leave it there when he gets up. He has too deliberately kept it beside him, not stuffed it under the seats. It's an in-house convenience-store brand, which probably shouldn't exist to begin with, and between it and the newspaper, surely he could have afforded something less idiotic for breakfast. The old woman across from us is watching him, too.  

The train pulls into the final station. He gets up, without the bag, and starts to go. "Oh, come on, take your trash with you", I say. "Sorry," he mutters before even turning, trying to flinch away from me but kind of bouncing back off the rubber edge of the doorway as he does. He retrieves the bag. There's a trash can on the platform, exactly where this door opened. He drops the bag in the trash and lingers there a moment, carefully looking away from me. The old woman walks around to the other side of the can and stops right across from him. He looks up at her. I'm behind him, and can't see his face. She puts on her reading glasses, inspects him sourly, and then nods. To him, to me, to herself.