(Note: I am sure other meetings such as N/A and others work the same way, however I am most familiar with A/A so I am basing my thoughts off my A/A meetings.)
There are four dimensions to the mind: perception, thoughts, behavior and affect.
Perception is the strongest influence and affect is the weakest.
Perception is how you view the world, make connections between events and comprehend what is around you. Based on your perception, you have thoughts. For example, if someone reads your text and does not reply for a couple hours, and you perceive that to be rude, you will think, "What a rude a$s bi#!h!"
Thoughts cause actions. If we continue with the same example, your action may be to delete the person from social media or ignore when the response finally does come through.
Actions trigger emotions, which to continue with the same example, may trigger anger, jealousy or sadness.
Now, if I told you, your friend did not reply because he/she was in a car accident and is in the hospital in critical condition, your perception changes. Instead of thinking of the person as rude, you think about how sorry you are that that happened to them. Your action may be to give a call or go visit. Your emotions will be of concern or pity.
Perception changes the domino effect. Addicts and Alcoholics have an "action" (behavior) problem because our perception and thoughts are inaccurate.
Meetings help put our perspective back in reality, thereby changing our thoughts to be more positive and accurate which changes our actions and then feelings.