What is the old Chinese saying, Learn to run today that you may live to run tomorrow?
Which ties right into the idea that the best fight is the one you are not in.
There are times when you need to back away. In the DAAT model police officers always have two choices: disengage or escalate. Cops can't just walk away and let a bad guy disappear, but we can disengage, call for help and keep an eye on the subject until the cavalry arrives.
On the other hand, a civilian, even a CCW holder who is legally carrying, should consider taking a step back from the situation and acting as a good witness. You don't always know what's going on and it really isn't your job to find out. Remember you are making a serious decision to get into the middle of an altercation. Such a decision could turn deadly and if you think your life is busy and confusing now, imagine what would happen if you were involved in a shooting.
The delicate question is: Where can you do the most good and the least harm? Often that will be from a distance directing the cavalry.
Once in your life you might have to step in. That's why you need to train and be ready. Because if you do step in, you have to do everything right to protect your life and your freedom. But remember, you always have the option.