I have a 1st deg blackbelt in American Kenpo and have trained in Kajukembo, Kali and Salat as well. All told about 15 years of martial arts practice. I would say a bit of training will not do you much good unless you practice often. Knowing a technique in your head isn't much use if you don't have the muscle memory to execute quickly and under stress. Even better if you can practice in a sparring situation to help you get over the shock of getting hit. I've seen a lot of people just freeze the first time they get hit hard. In my Kajukembo dojo, we called the bruises "honor tattoos". It wasn't just the guys with testosterone poisoning... it was considered important to know how to take a hit as well as how to avoid one, because in a self-defence situation, the chances of getting hit are pretty high.
Even if you carry a fire arm, you need to practice often, not just shooting, but getting the gun from your holster/purse/glove box to your hand, getting the safety off, etc, all without losing sight of the threat. I taught some self defence seminars for women and would always ask who carries. I would them give them a rubber practice handgun and tell them to put it where they normally carry theirs. I would then stand about 20 feet away, tell them i was going to attack on the count of three. In 2 years of teaching that seminar, not a single person could draw on me before I attacked them. From 20ft, with a count down.
Your best defense is always situational awareness and trusting your gut instinct. If the situation doesn't feel right and you have the urge to leave, don't talk yourself out of it. Just go.