This is precisely why I don't do every single thing. If I complete every single side quest, fight every boss, level my characters, get every item... I've beaten the game. That's it. I have no desire to play it again for a very long time.
I play for the story. And the best way to get the story out of a game is to play the story related parts uninterrupted. I also hate grinding for levels. I keep my levels as low as possible. It adds something else to the game: harder boss battles. Bosses should be challenging, not pushovers. Too many times they end up being too weak even if you gain a normal amount of levels.
When I've finished that, I can play the game again. Then I can worry about completing everything and take my time doing it.
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