Once upon a time...

"(...)
Feeling unsure, the girl thought the best thing was to put her heart in a safe place. Just for the time being. So she put it in a bottle and hung it around her neck. And that seemed to fix things … at first.

(...)

Although, in truth, nothing was the same. She forgot about the stars… and stopped taking notice of the sea. She was no longer filled with all the curiosities of the world and didn’t take much notice of anything…

(...)

One day, while walking on the beach where she had once strolled blissfully with her father, the “girl” — now a grown woman — encounters another girl still little and still filled with the boundless and buoyant curiosity that had once been hers. Suddenly, she is reminded of all she lost when she locked away loss.
(...)

So she sets out to liberate her heart from its glassy prison — but the bottle has been fortified by years of self-protection. 

(...)

The bottle couldn’t be broken. It just bounced and bounced … right down to the sea. But there, it occurred to someone smaller and still curious about the world that she might know a way. 

(...)

The heart was put back where it came from. And the chair wasn’t so empty anymore."

in The Heart and the Bottle 

Oliver Jeffers