Air. The element that Aang already knew and so, does not have to learn it. But what if he did? Where does Air fall into the Avatar Cycle anyway? Does it go before Water or after Fire?

Reasons for before Water:

1. Aang, a mere 12 years old, has alreday mastered it. Many citizens of the various nations know how to do some form of bending, but very few are actual Masters.
2. Air does not seem to be as complicated because it is very quick and choppy, meaning that it does not seem to take a certain amount of skill to learn the moves, unlike the other elements.

Reasons for after Fire:

1. To learn Air,??the Avatar would have to lead a strict lifestyle according to the Air Nomads' style of life, unlike any other elements. This could quite potentially be very difficult.
2. Air can be used in several of the other elements, as Aang has demonstrated by using airbending along with other elements, like how he used air to speed up his attack on the drill with the rock wedge.

So, what do you think? I believe that it comes after.??