You might be aware ...

.
... and then you might not:

Ask any cognitive psychologist or neuroscientist the same question, and they will tell you that consistent awareness is nearly impossible for the human animal. Some of them will even use highly amusing videos to explain basic concepts about how awareness works—and how it fails.

Here's the first video Ms Jackson refers to (and yes, I failed!):



Consider, then, what Joseph Wilcox did or didn't see. Amanda Miller was reportedly not 'with' Jarad, and ambushed him. He likely never saw it coming.

But just like the police officers who were assasinated, it can happen to the best of us.

pm