The chance encounter seemed to be the beginning of the story for them.
He thought he would continue to wander like this. And her always quiet presence made him ignore how much she meant to him. Until he was shocked and wondered if he could still stay in her heart.
She walks the same path he has walked, and goes where he has been. Stop after stop, it's memories and farewells. She thought that for him, maybe she was nothing more than that, and she still had to leave after a short stay.
How much time and distance does it take to reach your heart, and how many light years does it take to stop. . .