You don't know what you don't know.
Simple things become really hard to accomplish under stress.
The square range is not the real world.
It happens faster than you think.
Make the bad guy play by your rules.
The armed citizen needs to know more than just defensive tactics and how to shoot.
A flashlight and a firearm are two different objects.
Being aware of your surroundings and everything going on around you, that's what.
Safety first, safety always.
Keep your friends close, and your defensive firearm closer.