We've seen the Korra season finale, where she finally unlocks the spiritual side of her role as the Avatar, fully connecting with her past lives, where Aang gives Korra her bending back and the ability to recover the bending of others. The source of taking one's bending away is unknown beyond the fact that it deals with pressure points and bloodbending; the bending revivification is also a mystery. However, that isn't the topic of this blog.
The topic of this blog is the Avatar State. Many fans of the original series will recall that Aang had to go through a grueling, difficult, emotionally draining process to unlock all of his seven chakras in order to master the Avatar State. But how does a spiritual energy boost from Aang allow Korra to completely skip a process that is assumed to be gone through by all previous Avatars? It could just be the creators doing it because they can, but before I label it as merely the author's will, let's take a look at it.
As I stated above, an Avatar must go through the chakra-opening process in order to master the glow. But between the first and last episodes, it isn't even hinted to that she went through the process, so we can only assume it didn't happen. Maybe the creators decided to not make it a big show, but make the process of each chakra the theme of a certain episode. A theory was made about this concerning episodes 4 and 5, where Korra dealt with fear and romance, respectively, which are both aspects of opening certain chakras. However, this is the only place where I've seen any aspects in opening chakras; unless you look at it extremely subjectively, you couldn't really relate chakra blockages with episode themes. So that theory is most likely out. So then how did she master the Avatar State? My answer is that she didn't.
This is a theory of mine, and is based off a few facts and some logic, and I don't even necessarily support it. But something that I thought of was that there are multiple aspects of the Avatar State; the physical (dealing with the four elements) and the spiritual (dealing with chi, energy, and whatever else). Korra was about as unspiritual as an Avatar can be, so she couldn't connect with her spiritual side, including the Avatar State. Aang, however, was her polar opposite; passive, pacifistic, and very spiritual. So he was able to enter the Avatar State much more easily. Korra was in intense, high-emotion situations like Aang, but because her spiritual connection was abysmal, she couldn't trigger the Avatar state, so she never went in her out-of-control rage state. She connected with her spiritual side finally, which Aang probably did at a very young age, but she was never in a fearful or enraged state afterwards, so she never went out of control. I say Aang just unlocked the Avatar State in general, and gave her a skill involving one aspect of it. I do not think this means she fully mastered the Avatar State.
For an example of this, we'll look at Aang himself. Like I stated above, Aang mastered the Avatar State (almost) at the end of season 2; he fully did at the end of season 3. But after he fully mastered the Avatar State, he used a technique that involved the spiritual side of the Avatar State; taking someone's bending away. He did exactly what I stated one paragraph above except in the reverse order. So, this means that if she didn't meet with a guru in the six months between the first and second seasons (if that is how long it is), next time she goes into the Avatar State she won't be able to control herself.
So, that's my opinion; now what's yours? Tell me what you all think about the whole Avatar State business, whether you agree with me or not. Sorry for the long post, and thanks if you actually read through it all.