“Dreams of the Sun and Moon!” quotes from Pokémon

You know what? It sounds like you want to become a Kahuna, do you?

Are you saying your dream is to actually become a Kahuna?!

Getting to know what the world is like is a very important step. You'll have a broader perspective once you expand your horizons. The truth is, it will allow you to look at yourself and find ways you can improve. Right, Ash? [Ash is confused at this wisdom] As someone who came all the way to Alola to train, you already know that, don't you?

[after thinking about what Olivia said about travelling the world to improve his skills, as well as realizing that his Alola journey is drawing to a close] I've got it! I've decided I want to go out and see the world! [Rotom Dex is confused] Pikachu, what do you say we go home? [Pikachu eagerly jumps onto Ash's shoulder] The world has more awesome things for us to see. There are tons more Pokemon out there! [Pikachu eagerly agrees to head into another new adventure. Keep in mind that because Ash officially won a League and is an official Champion, having Ash compete in more region Leagues after that would have been seen not only as a repetitive and tiresome storyline but also as a permanent regression in Ash's skills as a trainer.]