What does the boss mean when he says I don't use my brain?

That's true.

First: there is no logic in doing things.

A man with logical thinking knows how to think things through first, and then do them with the fastest and best speed and quality.

Second: speaking is not rigorous.

Lack of rigor is reflected in 1 lack of focus, 2 indecision, and 3 being faster than the brain.

Third: make progress.

No progress means that you have no development potential, and this kind of employee boss will not want it. In the end, the boss will definitely fire you under various excuses, which is very realistic.

In short, think twice before you act is to think vaguely.

I wish you success! I didn't speak well enough. I hope you can forgive me.