Answer:
In the poem "what love isn't," the things that love is compared to (such as a book, a movie, a fairytale, etc.) all have in common that they are unrealistic or fleeting. The poem suggests that these things are often idealized or romanticized, but they don't accurately reflect the messy, complicated reality of love. Love is not a fairytale ending or a perfect storybook romance; it is something deeper and more complex than that. The poem is ultimately trying to convey that love is not something that can be neatly packaged or defined, but rather something that must be experienced and lived through in all its messy, imperfect glory.