When life gets hard, Rachel, ever the song-writer, dreams up lyrics and chords and melodies in her head, imagining an audience awaiting for the final breath of the song, imagining the lights casting shadows as she lifts her arms, higher and higher —
She imagines the world at her feet, as she sings a song about a love lost and found, about a lonely girl with too-big dreams in a small world. In her head, she thinks that by the time she's old, and she's done her parts in all her favorite shows, and she's won her awards and bowed her bows, she might look back on those times she felt like there wasn't a person alive who wanted her.
She might laugh them off, she might tell magazines that it's where her inspiration came from, that all her hardships shaped her to the woman she was today, but subconsciously, Rachel can't imagine growing old. She can't imagine ever feeling like it was all worth it.
If there are three things Rachel Berry is certain of, it's that she's destined for greatness, she's destined for more-than-this and she deserves every last praise because she works for it all. Secondly, she's far too certain that she would welcome the end of high school. She would likely say heartfelt goodbyes and mean every one of them, but have no intention of returning to Lima. She would pack her bags and book her flight and arrive in New York and make it big. It's what she knows to be true, and nothing more.
And lastly, though just as significant as the others, she's vastly sure that no matter how far she flies, no matter how long she hides away in New York and studies in school and auditions for roles she knows she's worthy of yet may not get, there's a tiny tendril of her heart that still connects to Lima. It's like a piece of yarn that doesn't break, no matter how much she tries to tear it. On the other side, she imagines Quinn sitting at home in the small town, with a husband she neither loves nor hates, reading a book at her bedside, thinking she should have been worth more but never voicing it out loud.
She imagines that Quinn still thinks about her. Perhaps she's passing by the high school on her way to work, and she remembers in a flash loving Rachel Berry, and kissing Rachel Berry in the football field as the lights glowed around them after a big win. She might remember making love. She'll remember the eager face in the stands and the way her hand curled into Rachel's, her thumb brushing along the inside of her palm like a secret message.
Of course, this is all in Rachel's hypothetical future. She has a flare for the dramatic, you see. For all she knows, Quinn never gets married — Quinn might even come to New York with her, but that's something they don't talk about, even with graduation looming mere weeks away.
The truth is, when Rachel is thinking of her future, she doesn't think Quinn will be in it. Not because she doesn't want her to — oh, God, if only she could voice how much she wants it, craves it — but because the Quinn Fabrays of this world never love the Rachels. She fantasizes a world where Quinn loves her more often than she's willing to admit, but when her future plays before her eyes, Quinn is still here, in Lima, while Rachel spends the rest of her life in New York and loving her in secret.
One day, she'll write a song about loving a girl. She'll say something about her eyes and the flowers that match it, and if she's so bold, she'll try to explain the look that Quinn used to give her when she thought Rachel couldn't see. She'll express the way the snow looked in her hair, the way she smiled when no one else was looking, but mostly she'll sing about the inevitability of it all.
So when Rachel imagines her future, and she's successful, and she's rich, and she's growing old with her husband, she imagines that no matter how far away they are at this time, their hearts never once grew an inch apart.
Quinn marries and remarries, searching desperately for the one that left long ago, but still she'll be sitting at her bedside thinking she was supposed to get on that flight with Rachel long ago. Rachel thinks there will never be a moment that she won't grieve over losing her.