I am 18 and like a 21 year old, is this wrong?

I moved your post, since it is a new question,

The previous question had to do with minors, at 18 a person is no longer a minor and free to do as they wish

Why would it be wrong?

There's nothing wrong! It's probably perfect... :)

Thanks guys I was just checking people look upon age as a big thing at times, like 15 and 19 is seen as wrong yet 18 and 21 isn't? I understand why because 16 and 18 is like mildstones aren't they, but it just makes me think who decides what is right and wrong and its funny the way people adopt others attitudes and 15 with a 19 year old is seen as wrong! Anyway enough rambling thanks for your opinions!

It all deals with children and their protection, 14, 15 and 16 year old children often need to be protected from thierself at time.

thanks guys i was just checkin people look upon age as a big thing at times, like 15 and 19 is seen as wrong yet 18 and 21 isnt? i understand why because 16 and 18 is like mildstones arent they, but it just makes me think who decides what is right and wrong and its funny the way people adopt others attitudes and 15 with a 19 year old is seen as wrong! anyway enough rambling thanks for your opinions!

To me, it's not the same thing.

You're considered an adult at 18, not at 15.

You mentioned that 16 and 18 are like milestones, well that is not the answer. A 15 year old girl is not mature enough to deal with the things that are happening in her mind and body, and she can be very misled by someone older than her that pays attention to her and tell her things. This does not apply to all 14 year old girls but to the most of them.
An analogy to this is that the insurance companies charge a teenage boy a lot more for insurance than a 25 year old, because the teenage is not mature to realize the consequences of their actions but by 25 thy have matured to the point that they understand crazy things can have crazy results.

18 and 21 are adults to do what they want, if they know what they want.