Are you ready to be a manager? The non-negotiable skills

It has been a few days now that I have been pondering about this question.
When do we know someone is ready to be a manager?
When does your manager know you are ready?
When do YOU know you are ready?

And should you know you are ready before you get the position?

The only thing that is certain around this topic is that there are as many opinions as there are brains in the world. Not only human…