You have the fear of the unknown, the situational assessment and the instinct to respond to danger honed. If you were to eliminate another human it would be very swift using the element of surprise... Would you put up a behavior custom with will allow you to get as close as possible to your subject undetected to the point that when he realizing something wrong he would not have any time left for reaction?
You have learned how to generate impact kicking force in multiple directions. You have learned how to generate impact striking force with your hands, elbows and shoulders. You know you can even use your head for butting... You have learned a swift reach with a blade to available pressure points and how to use a blunt object as well.
You have learned technical deflection, blocking and evading impact, sharp and blunt object, learned about the split second danger of a bullet leaving the barrel and how to tactically prevent it from hitting your body.
Now you have the building blocks of getting a hands on experience to ensure success. The closer you are to your opponent, the less reaction time you have. Therefore there is less work needed to be done in long combinations in the short range which includes grappling, and short striking. However in the longer range which includes kicking, drop punching, and use of sharp or blunt extension you need to do a little more.
You have already calibrated your senses of assessing distance and speed through practice with your training partners. You recall that there is such a thing as a reaction time and you know how to deal with committed attack. As you see from historical events of daily news, when someone gets the urge to kill they use committed attacks most of the times. It is the world of Hollywood and the Martial Arts that hypothesize on the feinting.
The range is greater, and you had either not completed you response due to hesitation of transforming from a state of peace to a state of war, or your opponent sensed he wanted to use feinting.