User blog comment:FairyRaven/Fairy Tail Chapter 302: The Eclipse Plan, Review and Commentary/@comment-3416581-20121004180932

I have a theory in which the Dragons and the Dragon Slayers belong to the past (400 years ago) and in the year x777 Layla Heartphilia was forced through the Eclipse Plan to open the gateway to the past. She brought the Dragon Slayers to the present, and somehow this process erased their memories, making they think that Dragons have disappeared but they're actually coexisting 400 years ago. That explains why Igneel said the time for the dragons to take action as the Dragon King Festival is coming close, suggesting that the gateway is going to be open soon.

( Sorry for the gramatical errors, but I'm trying ^^ )

So, what do you guys think about it?