He hadn't exactly wanted to leave, but he hadn't had a choice. He would've taken the bottle from him, and what was in it. Another dragon had been visiting his...guardian, and had given it to him, and it had been pretty, and there was a pixie inside and- and his guardian hadn't been happy, and had wanted to take it, but he couldn't let them, he wouldn't. It had hurt, but he hadn't let go, and his guardian had thrown him away, snarled at him about seeing how he survived on his own.
And Tyau had fled, flying as far as he could.
But now, he can't fly any further. He's exhausted, and has dragged himself under what little cover he can find - the lee of a rock - and curled around the bottle he's still managed to keep a hold of.