When chihiro was about to leave Haku berkata don't look back what does he mean oleh that? I don't really get it.

No. Haku told Chihiro not to look back because if she did then she wouldnt want to return to her own world. Though Haku thought that if she did look back then she would regret not staying in the Spirit World with all of her new friends for the rest of her life and never really ever reconnect with her world again. Though if she didn't look back, Haku thought that she would still be able to continue her human life.

Spirited Away is my favorit movie of all time and this is the most beautiful piece I have ever heard. A while back someone wrote an unofficial version of Spirited Away 2:Return to the Spirit World. It is fanmade but really good. It is like a book except on a webpag. The menulis and story style is almost exact that of the original writer. anda can check it out oleh googling Spirited Away 2. Then click on the fanfiction link (It should be the first result) .The ending is great and anda should really check it out.

Because that a period of time has passed and it is unclear whether atau not time passed at the same rate.

Because if she did look back she'll be locked in the spirited world

Because Haku was afraid shed want to stay with him