So I've mentioned the sharpie test and the tueller drill.
Another reason you are dead within 1.5 seconds of encountering your first fast zombie, is adrenaline.
Most people who get attacked with a knife and survive to talk about it, say they never even knew a knife was there.
Or that they'd been stabbed, until after the fact.
In many cases, they think they'd just been punched, and are completely surprised
One reason the adage is "the winner is the one who dies in the ambulance, not the gutter," is because it's entirely possible to receive a fatal wound, not realize it, and then inflict a fatal wound on the other guy without *him* realizing it.
A dozen times within 30 seconds.
The marker drill teaches how you *will* get cut, fatally, without realizing it.
In full adrenaline freakout, this is even more pronounced.