Red can't seem to remember when he stopped smiling.
In a rare moment of peacefulness, his mind wanted to use this time to reflect onto the past. The past, he decides, is like a pain you can never shake off. Forgiving was okay, but forgetting was impossible. Diving into the past is like scratching at old scars. Reliving the past is to allow the wounds to fester and get infected. Even if his companions may not have enjoyed it, Red had left his past behind. After all, to him, the past was an old wound. Better to heal it and try to stop thinking about it, even if you cannot forget it.
However, peace was rare, but more common when he was younger. That was what pulled him into the past in the first place. Living with his mother was calming and peaceful. Pallet Town was especially abundant in its soothing atmosphere. He smiled plenty in his younger days. What had changed? He used to be young and innocent, so what changed during his journey? Red knew the answer already, but didn't want to admit it, delving back into the past in hopes to refute his belief.
Something had changed.
Maybe Giovanni had done something. He and Red weren't that different, after all. They did anything they could to reach a goal, even if that meant trampling others in their path. What had he done to Green again? That's right. He was Champion (the title was practically poison on his lips now) for only ten minutes. A laughingstock. Yet he couldn't help it, he wanted to become Champion so badly, he immediately threw away any type of compassion for Green. He hoped that Green was happy. Surely seeing his face on TV everywhere had been painful for him, right? So Red ran away, to Mt. Silver.
No, it started before that.
Perhaps it was Green himself. The lack of affection that he gave while they were childhood friends suddenly disappearing, replaced with spite and hate. Those taunts son grew old but something resonated with them. Turning a cold shoulder wasn't enough. Every taunt, every word was filled with genuine detest, as if he was his worst enemy. Did he do something wrong? Was Green just hiding it? Did Green really hate him? With those questions swirling around his head, there was no reason he wouldn't stop smiling. Knowing your best friend hated you was worse than being burned at the stake.
Red shook his head. He should stop lying.
It was his fault for not smiling. As things turned into routine, he just stopped. One day, he didn't smile. And that turned into weeks, and that turned into months and those months turned into years and suddenly, he forgot how. As the novelty of earning gym badges, catching new pokemon, and traveling to new places wore off, he found no reason to smile. In fact, did he even know how to smile?
At first, it was difficult. His face muscles moved, although unwillingly. However, as he did it over and over again, it felt easier. Even if it looked horribly fake, well, it was a start, right?