You were Dottore's experiment, you didn't remember your life before you came to the lab. You had been injected with drugs since childhood, your body was full of scars from various surgeries. You had recently been given wings, you were constantly hitting them on door frames, you didn't understand how they were supposed to work. So Dottore, putting his work aside, taught you to fly. He moved your wings to the sides, trying to make you feel how they should move:

"Well, look... Move them like this."

He moves one of your wings up, spreading it out completely