Many people say that the AT is about posture. I find the the word 'posture' is often loaded with feelings of guilt , beliefs of what is needed for 'good' posture and fears for 'bad' posture.
Personally I don't find it interesting to work with 'posture' even though my work definitely improves it.
I much prefer to work with balance, and for me that's what posture is about. When someone has a 'bad' posture I find that that person is out of balance. The support system for the body and mind is not working efficiently and therefore the working of the whole system, body and mind is compromised.
I find that unless one is suffering from pain because of poor use of oneself, (like maintaining a 'bad' posture), posture doesn't often have a big importance in ones life. One may ask, "so what, what's going to happen if I have a bad posture?" A lot can happen, just like smoking can have a huge impact on ones health, so can posture but not necessarily. It is true that you can have a healthy, even a happy life in a terrible posture, just like a chain smoker doesn't necessarily die in pain from lung cancer.
Now, have you ever thought of what would happen if you had better posture, or better balance in your life? A lot would happen, guaranteed.
When you align your body in a way that it is in balance you release of lot of tension which is costing you a huge energy bill continuously without you noticing it. Your organs will have a lot more space to work efficiently, and pretty much all functions in your body will improve (digestion, breathing, brain activity, balancing of the nervous system and emotions...) It is proven that learning becomes easier and many have experienced that creativity improves from better body alignment and balance.
Personally, I know many people who don't notice 'bad' posture having any effect on their life. In contrast, I have not met one person who doesn't feel immediately something of the positive effect that better balance brings, and many have experienced life changing transformations through the long term effects of finding better balance in their life through first finding the balance how the head is resting on top of the spine.