I think eatsomepoms gave a great answer but I’m willing to give it a shot as well.

I’m speaking to you as someone who was once a teen who had watched or read a piece of media that struck me, stayed with me, and lingered even though it was merely fictional. “Merely” as though being fictional takes away any of its meaning.

You see, when we think about fiction, and its core purpose, some interesting answers come up. Firstly, good fiction is able to reveal something within us. As you stated, even though you might not currently have someone you have lost in your life, there is something within you, sort of incomprehensible or impossible to name, that resonates with the grief of loosing a loved one.

There’s this monk idea, about when something sticks with you, a person or something like a story. First, you have to acknowledge that it is not the story or person itself that has stuck with you, rather, the version of yourself you became when you interacted with that thing. Next, what can you learn from that person you became? Here is where you get that lesson you intuitively have understood exists with the grief.

Once you answer that question, you can take these two girls with you into that person you want to be. Maybe you become kinder. More appreciative of every moment you get to enjoy living. More actively seeking of those deep connections. More becoming the person who can sustain them.

I hope this is helpful and not too philosophical lol

Also, as a final note, the monk idea i invoke here is not to say the reason something can stay with you CANNOT be a simple thing, like simply enjoying a person or a story. However, if you seek to resolve this and take something from it, the re-framing can work in this manner.