The dojo is actually probably one of the safest places in the world. In such a place you are learning how to protect and take care of your body while your fellow students and teacher look out for your well being and safety.
The dojo is the time and place to make mistakes, and to be made aware of their corrections so when you exit the dojo and enter the “real world” you won’t make those mistakes.
Zanshin “awareness” exists on many levels.
When training at the dojo how aware are you of the other students around you?
Even knowing 100% that they are not going to attack you, you still have to be aware of more then just the interaction between you and your current training partner. What if another student falls over and into your training area.
Weapons often come loose in the hand and go flying. You need to be both aware of the here and now where you are training, but also have an awareness of what could happen- so if it does happen you won’t be taken by surprise.
Another common mistake made during training is when the technique is over.
For example, lets say I’m practicing defending myself from a punch. In the dojo, because I’m trying to learn a specific lesson there is often only one punch to which I apply x action.
Even though I know it is a training exercise and that there will be only one punch,
I need to keep my awareness up just in case another punch is thrown. You never want to get into the habit that “all is safe now”.