It comes to him easier than breathing.
When he first opens his eyes, takes his first gasping breaths of air, it hurts. His heart thumps violently in his chest, beating against his bones and loud in his ears.
He feels new, and strange, and he aches.
Jack blinks hard against the fuzziness in his eyes. It feels like he has a layer of ice over his pupils, making the world fuzzy. He can't see much more than vague shapes, fractured and multiplied over themselves. He doesn't see the staff before he kicks into it.
The clatter of wood against ice eases something in him. When he picks it up, when his fingers wrap around wood that is warm and comforting against his palms, something wild inside of Jack stops fighting to escape his skin.
His fingers are soft and relaxed against the wood. He's easy with years of muscle memory, and the frost blooms without a thought. It spreads across the ice of the lake, with great big whorls and whirls and he can see so clearly now. It glitters in the moonlight, and Jack laughs with the sheer joy of it.
Free from the cold, and the dark, the pain from waking hasn't faded. It will stick with him through a great many years and existing somehow feels just a little bit wrong. But this - the frost blooming across tree trunks and windows and statues, this feels like so much more to Jack.
Everywhere he goes, every place that he blows through, Jack Frost leaves a mess of snow, and ice, and frost. He delights in the best parts of himself, the fun and mischief of Being Jack Frost. And while the children don't see him, they will shriek with glee in the early mornings, when the frosted ice on the pond is at its most other-worldly. They race to be the first on the ice, clumsy in their desire to become a part of winter's wonderland.
Eventually - eventually Jack will turn around and see them, too. Some day, Jack will realize how much his messes mean to the people he's left behind.