Part of what you are practicing with learning Alexander Technique is a new way of using your attention and thinking. If you remember back, it was a little overwhelming when you first learned to blow a now-favorite musical instrument or when you learned to drive a car. As you practice, new ways become much easier to sustain, no matter how strange it felt when you began.
Most people favor a certain way of using their attention and exaggerate it because it is the only attention style they know. There are many variations on applying attention. Perhaps now your attention works somewhat like a searchlight or field glasses - whatever you direct your attention to takes up all the capacity you have. If that were the case, a great deal of effort would be required to redirect this kind of all-absorbing attention. The same would be true of having a butterfly-like attention span of only a few moments. Your ability to appropriate the quality of your attention is stuck - no matter what the pattern it's stuck in.
The brand of attention that the use of AT cultivates could be described as a widening of the field of what is going on at one time; a multi-tasking ability. You also learn to shift your attention lightly, easily and precisely. These are qualities that most people find unusual.
Secretly, there are also more effective and strategic moments for when to apply the process of AT rather than just generally whenever you can remember to do it. Some people find that a little thought to making what you're doing easier is best applied before intending to act. Try experimenting as you start moving and during pauses as you continue doing the action. The preventive strategy behind this works because once a habit starts and assumes full control, it is more difficult to stop it. So the way you start what you are doing determines how you are able to continue doing it.