User blog comment:TheCarrotSaysYumYum/Dragons, People and Demons.../@comment-3987368-20120721105325/@comment-3987368-20120721145136

I'll do that :) and sure, it kinda makes sense.

Actually, I had a similar theory until I bought FT Volume 15. In the Q&A section, it mentions that Volumes 4 gives Natsu's age as "unknown" and Volume 13 gives the same for Gajeel's age.

There was also something about that kinda conflict between Lost Magic perhaps not being recognized by newer magic. I did think that was the reason behind the inability to exit the barrier, but then I remember that Rustyrose's Belfast the Hurricane being controlled by Bickslow's and forced to destroy itself by magic, which is not a Lost Magic. This made me think the theory about dragon slayer magic being lost magic and thus preventing the 2 from exiting the barrier to be wrong.

In fact, someone posted a theory elsewhere that a dragons lingering presence slows down time, meaning many years could've passed in reality while it was possible for only a few years to have passed for Natsu and Gajeel. This is theory, of course.

So much theory XD