I think i found out Natsu's "age" in fairy tail

{SPOILER ALERT}

Ok so, this is a little but of a stretch but since we all know Natsu has existed for around 300 - 400 years now, (since he is E.N.D) we can safely say we know why Natsu cant get through the enchantment wall during the Laxus arc in the first season (no, I dont rlly know why Gajeel cant get threw it). Now with that, since Natsu seems to be the same age as grey, and since they seem to grow up together and age together, i would have to say that Natsu's HUMAN body, is around 18 - 20 years old by now.

To sum it up, Natsu has Existed for 400 years, but his Body has only been around for 18 - 20 years.

I hope this gives a somewhat decent answer that nobody will ever really find.

(yea i know this seems bizarre and stupid but i needed to get this out of my head to get peoples opinion on it)