The poem describes a young woman who lives mostly in books, bored by ordinary life and hungry for adventure and love. Real relationships haven't been kind to her. Each time she opens up, she gets hurt, and the poem pictures her heart as a sleeve-worn thing, battered, broken and stitched back together. She has also lost people, and the speaker says a piece of her went with them.
Then the tone shifts. Someone new has appeared, and he or she is moving slowly, which she quietly appreciates. She wants to tell this person everything but fears being abandoned. Trust grows daily, even though her better judgment warns her off, and every day she risks a little more.
The final lines turn directly to "you," asking the reader or the new person to be careful with her. The mood is tender and anxious, hopeful but fragile, like holding your breath while something delicate is placed in your hands.