Most self defense experts agree that awareness is the first and most important concept in personal protection. You can’t defend against a threat if you’re not aware of it. Pretty simple.
It’s undesirable, and not possible to walk around in a state of paranoia, where you’re acting like there is always an active threat.
So, how do you consciously adjust your awareness level to be appropriate for the level of threat? Here is a simple color coded guideline to use, that’s been in use for years.