She knew.
She had denied it to herself for years, tried desperately to live in ignorance.
But she knew.
Toph and Sokka.
The chemistry between them was astounding to her, how could two people be so utterly perfect for each other yet not realise it?
She knew that if they were together they wouldn't share the awkward silences that so often filled her eardrums.
She never knew silence could be that loud until she realised that.
She knew that if they were together their banter would be natural and playful, sounding as though they were best friends.
She spent her days analysing her own stiff, formal conversations with Sokka after she realised that. Her voice was sharper than a blade and she knew it cut him.
She knew that if they were together their fights would last mere minutes, seeming trivial in retrospect to all others except them, but they would not hold grudges. Their fights would be playful, never scaring the other.
She held her hands against her ears, willing the memories of her shouted arguments to not break through the wall she had built to keep them out. Every time one slipped through it felt as though it was inflicting physical pain upon her being, and she knew it was inflicting psychological pain upon her soul.
She knew that if they were together, each touch that passed between them would be tender and loving. He would look into her eyes as if he were a blind man, seeing the sun for the first time.
He hardly ever even looked at her anymore. Each time he did, she could see the pain behind his eyes, wondering why she had shouted at him, or refused his touch. Even now, as she was trying to put it into words, she found it difficult.
She knew she just would never be good enough for him.
She knew that if they were together, they would travel the world. Seek new experiences and adventures. Toph would never let her lack of sight stop her, and Sokka would never admit to having a disadvantage because he couldn't bend. Their world would be full of bright light.
She hadn't left the house in days. She had just been sitting here, in the dark, refusing food or Sokka's presence. She felt so bad, inflicting pain on him like that, but she would feel worse if she had to face him, to tell him that she wasn't good enough and that he should be with Toph.
She didn't want to do this, but she couldn't not. She waited for the ink to dry on the parchment she had written on. On it, she wrote her goodbyes to him, her family, her friends. On this single piece of parchment, she begged him to realise what took her years to figure out, he was made for Toph, and they were two pieces of a whole and would never feel complete without the other.
He never heard her whispered 'goodbye'.
The only answers he received were written in black ink, the same colour as the shadows she had immersed herself in.
She knew it was never going to be easy, and she knew that it would take some time.
But she knew they would be perfect for each other.
She just knew.