I forgot to emphasize the last part of situational awareness: choosing the appropriate response to risks/threats. One has to practice both the ability to judge quickly, and reflect on all the possible choices, to improve the ability to judge wisely.

One personal example: I've been accosted twice by strangers making inapproprate sexual comments to me in a bookstore. The first time I chased him out of the store, the second time I reported the person to the manager. The judgements I've made:

1. Never read in a public place: My situational awareness drops to zero (I have no idea how long these wierdos were talking to me before I noticed.)

2. If this ever happens again, prevent them from fleeing, or if unable; be sure to get the GD license plate number, so the police can do something about it.

Bluecimmers