Luna Lovegood had a secret.
It wasn't as if she tried terribly hard to hide it. She skipped through the corridors, for goodness' sake - she wasn't the most subtle of people, not with her Hufflepuff scarf (Ravenclaw girl that she was) and her butterbeer-cap necklaces.
She sometimes thought, later, that Ginny felt betrayed - that she'd felt decieved. But Luna hadn't done anything; not really. She hadn't lied; in fact, she'd tried to tell Ginny many times. But something would always catch in her throught and make her quiet.
Remus, after all, told her - explained - that people wouldn't understand. And as much as Luna was used to people not nderstanding, to their being blind to the world around them, she knew that to say what happened behind closed doors was unwise.
So she kept quiet, quiet: Luna, with her wide eyes and light hair and innocence, she kept quiet. Some would say what she carried with her was dark. But Luna was not dark: there was not a thing about her aura that was capable of such. To her, her secret was just that: something untold. If anyone had asked... it would have come out. But no one did ask. That was the trouble with being an outcast, she thought - no one ever wanted to look very hard.
The moments were quick and silent, (almost,) and gone (forgotten) by the next morning, but they existed and for Luna, that was enough, to have her little secret locked away with a golden key.
Luna Lovegood had a secret: she was in love with Remus Lupin from the day she first saw him; and no one ever knew.