User blog comment:Natsu11/Zeref and Natsu?/@comment-77.103.156.124-20130712205017

what if? Acnologia, Zeref and Natsu were brothers 400 years ago and something happened to Zeref and by an accident he caused Natsu to have amnesia once every few years, and Acnologia to become the black dragon of apocalypse and after that happened he learned the value of life because he lost his brothers whom he loved very much. After all of that happened Igneel found Natsu wandering around with no memory so he decided to make him a fire dragon slayer after Zeref found out that the Dragon slayer is strong enough to kill him he went to Igneel and gave the scaly scarf and told him to give to Natsu for protection against him in case they meet before Natsu becomes strong enough to kill him for what he did to him and Acnologia. That's my theory anyway.