I had posted something before regarding awareness, not sure if it was here or not.
Being constantly switched on will burn you out quick. However, you CAN achieve a fairly constant state of awareness, and maintain it almost indefinitely. Its just a matter of being a little more aware of your surroundings. Most people do it every day-they just dont know it.
An exercise I do with my nephew is to go for a walk, and talk about whatever-then quiz him on people we have passed, or the color of houses, or how many people were in a car that drove by-simple things. The idea is that, no matter what you see, you CAN retain it-and once its retained, you start to become more situationally aware.
Of course, there are other ways to accomplish this too. Little brain teasers you can find online, simply observing the outdoors, its just a matter of being more aware.
Me, I am sometimes hyper aware (according to the GF)-moreso when driving or in crowded areas than elsewhere. She says I am the safest worst driver she knows...I am just always aware of whats around me-cars, pedestrians, sidestreets, etc. It isnt a trick-its just doing what your supposed to be doing-paying attention while driving. I am TRYING to teach her...