18 is the legal age of becoming an adult
Yeah, you are right most countries have 18 as the age of majority. In New Zealand its 20. :c
In some parts of the world, we are all legally adults from the age of 14. :U
16 is the most exciting birthday I think, because you get a lot of legal rights and abilities. 18 is pretty great too so you can legally sign documents. But 20 is neat because yay its a new chapter of life.