Philip Smith wrote:
By definition you cannot prepare for the unexpected.
In my opinion you have to just live your life, you can't walk around in a state of constant paranoia where you think you're going to be attcked at any moment.
That's one of the nice things about awareness training. First it is really similar to paranoia, but with time it becomes subconscious and automatic, running in the background while you "just live your life" as usual. An example (although a pretty boring one):
Some time ago I was walking in the inner city, minding my own business. Suddenly, a young couple about 10m to the front and left *really* stood out from the crowd. I didn't even see them before, but in the next second they were the center of my attention. It took me a couple of seconds to realize that it was because they altered their movement to a perfect "intercept course". I'm sure they didn't even notice it, but my awareness immediately alerted me. No paranoia involved at all.
It's still very rare for me to experience that kind of awareness, but it'll improve...