After having taken tae kwon do and judo for many years and like some of you having to leave it due to knee injuries from kicking air so many times I also had to give it up.
I was a correctional officer in addition to being a butcher and about a dozen other things in my life so far but I learned some training as a CO that really opened my eyes to the whole "self defense" industry. And as some of you have said, it is an industry. You really need to find someone in one of the deadlier arts to really protect yourself.
As a CO you are told to sign a paper saying your life will not be bargained for in a hostage taking among other things, so it puts things in perspective. The training is more survival defense rather than self defense. It taught one how to subdue or injure very quickly and it ain't very pretty. In fact, like wing chun ( I believe is the close contact one, I may be wrong or incorrectly spelled) much of the damage must be done without throwing your limbs out into the fray i.e., kicks, telegraphed punches to the head, etc.
Fights are over in seconds and its usually the first guy who lands a good shot. There is no glory in fighting in the street or for your life or anywhere for that matter. Unless you are a Bruce Lee, some skinny little street fighter will kick your ass every time. I've seen massive powerful men roll around the floor scratching like women and biting and doing anything they can to basically kill the other guy. It's rage, it's instant and there is NO time for thinking. It's like any sport, you're body is moving and your brain is just watching it. You shake, you drool, you bite your own lips and tongue, etc and sometimes you vomit afterwards.
First and foremost, you do not fight, you leave the scene if at all possible. If you have to fight, you don't wait to defend, you wait until the enemy enters your range and you strike at nuts, eyes, throat, solar plexus and a nerve centres and you run like hell. You don't stand around to admire anything, you hit until they stop advancing and you run like hell.
These days, everyone is carrying something so it's not even worth it to fight it out unless you are cornered.
If you want to learn to defend yourself look up SURVIVAL self defense. There is a really good guy up here in Ontario who does training like that. I'll see if I can find him again.
Don't ever kid yourself that a black belt in anything makes you king of the street.
It is so much a change in psychology as well. That's a big part of it. Ask yourself, are you able to strike a person as hard as you possibly can in the throat or stick your fingers deep into someone's eye sockets or will you freeze or just go into a defensive posture?
It's not even like sparring, it's survival, there are no rules.
Like some of you have said, you have to do it so often it becomes an auto-reaction. But it is also a journey in knowing yourself. What are you capable of doing to another human being if you or your loved one is threatened.
These days we are all more likely to be threatened so it's probably a good idea to take up some form of protection but make sure it's useful in the street because buddy isn't going to be some sparring partner in a structured classroom. He/she wants to really hurt you badly or kill you and you should be prepared to do the same if adequately trained.