I know Natsu was 7 (or so speculated) when the dragons left. I know he was sent forward in time when that happened. However why doesn't Natsu remember what the world was like 400 years ago? I mean I think he would notice a difference... even if he was only 7. Was his memory altered or something?
I don't think there was much of a difference between the world where Natsu went to sleep, and where he woke up.
For the most part, he spent his time with Igneel in the woods - as I assume a dragon wouldn't be welcome in towns.
I think Natsu grew up in the wilderness, went to sleep in the wilderness, and awoke in the wilderness 400 years later, not noticing a change because the wilderness couldn't have been different.
Natsu was just an Kid when he joined fairy tail but it never mentioned his age at all so natsu age is an unknown
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