I have a question:
In Majora's Mask, when Link uses the song of time, he only goes back to when he first entered Termina, not any time before.
Do you think that's because he can't?
Think about it! Termina is an alternate reality to Hyrule! With parallels including people, and certain locations. So since Link never finds an alternate version of him (at least not one I'm aware of) that means he doesn't exist their at all, making his first steps out of the clock tower his first moments of existence in that place! I know people have canonically gone back to before they were born in other places in media, but Link appears to replace his past subconscious with his present one when he goes back, meaning there's no way he could go far enough back in time to prevent anything, and likely wouldn't be able to time travel out of Termina since it's a parallel dimension, not time.
Just a thought.
What are yours?