Elizabeth Jane Howard said this quote

Charity felt crumpled and wrung out after her cry, like a sponge that had gone through a week of dishes. Of course Lady Beddington said things would be better in the morning, after a good night's sleep. Charity found it was a struggle to believe her; but then it was a struggle just keeping her eyes open. By the time the guest room was ready, Charity was sprawled out face-downwards on the sofa, sound asleep, her tears already forgotten. And that's what it means to be young, Lady Beddington thought, smiling.