From the perspective of an outsider the dojo appears to be a dangerous place.
Getting thrown and hit.
Under the watchful and critical eye of an instructor who seems to notice and correct the slightest mistake.
Who would sign up for that?
The dojo literally deals with the ways of life and death.
One is learning a warrior tradition literally passed down from person-to-person for hundreds of years.
That transmission is pure and needs to remain pure.
Yet, from the perspective of the student, that dojo is the safest place in the world.
Mistakes need to be corrected, in the dojo you get to do it over, learn from the mistake, get it right the next time.
Outside of the dojo, the wrong movement of a mistake has a different outcome.
Inside the dojo, one has the support of the group. Everybody wants you to get better, to be the best martial artist, the best person that you can be.
You are pushed and taken to the level that you currently are, in order to build and get to that next level.
Corrections by the teacher are done out of love and compassion. A martial arts teacher corrects because they know what can potentially be on the line, and they want you to be able to correctly deal with it.
They correct as many times as needed, in order to protect the student outside of the dojo.
The dojo is a mysterious place for those outside of it, but for those inside of it, a place of natural understanding.