Training is nice, but shooting isn't like ridding a bicycle. Training itself is useless if there is no follow through, meaning, regardless of what quality class you go to, if you stop there, it does you no good.
You must practice the lessons presented in that training, I don't mean shoot a qualification course once or twice a year. I mean weekly at the minimum. Dry firing is cheap and can be done every day, anywhere.
If you have read any of my post you'll notice one of my pet peeves is the abilities of LE to shoot. On the average, they are trained at the academy, qualify once or twice a year and that's it. Sure there are exceptions, you have those who seem to live in the range. But those are the minority.
The same with those who carry for self defense. They spend big bucks for a high quality training course and that's it. They carry their SD pistol/revolver for months without ever firing it. They are no better then those who get no training.
Let me give you an example. I'm a high power shooter. I use to be pretty good. I retired and moved to Wyoming where I have to drive 300 miles to a match. That's fine. Then gas prices go sky high and I back off. A couple years later I find a match closer to home to attend. Turns out I suck real bad at high power. Not because I haven't been trained, but because I don't practice.
The same thing goes for training and practice for self defense carry.