Consider Helen Keller's situation. As an infant, she is deprived of all visual and auditory (sound) sensations. Think about the enormous difficulty of understanding why she should have to sit still, why she should not attempt to swing her arms and strike at unseen things or people trying to move her in ways she does not want to go, why she is being restrained for no reason she understands. The wild and undisciplined girl Helen becomes is not a surprise.
When Annie Sullivan agrees to attempt to teach Helen, she is engaging in a battle of wits and wills with this child who has no understanding of what is happening or why, who has always been allowed to do whatever she wanted because no one knew how to treat her otherwise. Annie's work with Helen was challenging and enormously frustrating for both of them until the "miracle" of understanding breaks through Helen's handicaps.
Once those obstacles are breached, Helen's growth truly is miraculous. From the depths of isolation in darkness and silence, Helen grows into a strong and capable woman whose example and work provided inspiration to many others around the world.