If your self-defense plan starts with "I'll just react when the time comes," you need a class. Fear is real, fine motor skills degrade under stress and muscle memory is not a myth. Stay prepared folks!
I used to think just reacting was enough, until I did a defensive class. Those stress drills really opened my eyes. You can't rely on skills if you have never practiced them under pressure.
Thinking you’ll “react” perfectly when it matters is a bit of a fantasy. Under stress, you fall back to your lowest level of training. So either get enough training or accept that freezing might happen, there’s no in-between.