You don't know what lit it, exactly, but you can feel it.
A fire burning within you. Warmth and power.
It feels right. Like an engine, running for the first time. Like there was an emptiness, something missing within you now filled, it's absence only apparent in hindsight.
Within you, the flame rises - flaring and burning, roiling and leaping. Until one day, waking up in the morning, and shaking off a half remembered dream of flight, you stretch your arms and let out a roar.
A powerful, snarling, roar - a roar that no human throat should be able to make. As you open your eyes, stunned in the aftermath of such a sound, you swear you catch a drifting ember dissipating in the quiet bedroom air.
Shaking your head, you raise your hand to push your hair out of your face, and - wait. Is there something on your forehead?
A rush to the mirror.
Your eyes are slitted and striking, flecked with scintillating specks of metallic color. Small, young patches of shining red scales speckle your cheeks. And poking through your hair are a tiny pair of stubby horns.
You expect to be shocked, to be terrified, but... instead, you smile, and your eyes tear up. You're beautiful. For the first time, you look into the mirror, and recognize yourself - your real self - in the piercing gaze staring back.
You close your teary eyes, smile, and let out a pleased little purr. Another noise that a human throat would struggle with, coming as naturally to you as breathing. Because why would you be limited in such a way? It's become quite apparent now -
You were never human after all.