[Jack Bando]

"Then when someone travels to the future, that future becomes their present and when they go back in time they can't change anything... see how this makes no sense?"

But the future they warp to is still the future of their world, so they can go back.

"He knew which book to give her because he saw it. The first time she got it another way."

So shouldn't Charlie have had 2 books then?

"Agreed, but since the events of this season didn't start until after Hiro went back in time and started the chain reaction that changed everything, this doesn't mean much."

Hiro was ALWAYS the Kensei of legend is what I'm saying. Japan is saved by some guy calling himself Kensei (Hiro) and it's told to all of Japan for 300+ years (Hiro in modern time), so when Hiro is accidently in the past, he knows what to do.

Anything you do in the past either won't change the future, or is what actually happened in your version of history. (Twilight Zone episode where guy goes back in time to investigate a fire, he accidently WAS the cause)