What you describe is how it happens to everyone: magic does slide through you, and disappear, and come back later looking like something else. And I'm sorry to tell you this, but where your magic lives will always be a great dark space with scraps you fumble for. You must learn to sniff them out in the dark.
Robin McKinley[Gonturan] is a true friend, but a friend with thoughts of her own, and the thoughts of others are dangerous.
Robin McKinleyThe weak grey light that serves as harbinger of red and golden dawn faintly lit my window. I fumbled for a candle, found and lit it, and by its little light saw that the rose floating in the bowl was dying. It had already lost most of its petals, which floated on the water like tiny, un-seaworthy boats, deserted for safer craft. "Dear God," I said. "I must go back at once.
Robin McKinleyThe magic in that country was so thick and tenacious that it settled over the land like chalk-dust and over floors and shelves like slightly sticky plaster-dust. (Housecleaners in that country earned unusually good wages.) If you lived in that country, you had to de-scale your kettle of its encrustation of magic at least once a week, because if you didn't, you might find yourself pouring hissing snakes or pond slime into your teapot instead of water.
Robin McKinley