About 25 years ago, master trader Rich Dennis had a the old "nature vs. nurture" debate with a partner about whether traders were born or made. Dennis asserted that they could be cultivated, just like some turtles he had imported from Thailand. Hence the nickname "turtles" for the human guinea pigs in a financial lab experiment.
Since he had doubted Dennis, the partner was given the job of actually recruiting the trainees. One of the interview questions was something like: "Suppose you had completed our training program and selected a trade using our methods. Then you found out that the boss (Dennis) was doing the opposite. What would you do?"
The "correct" answer was, "If I liked the trade, I'd do it, even if the boss were on the other side."
What had happened was that Dennis had started trading against his own system, and needed some "straw men" to compare himself against. The "turtles" (who only knew how to follow the system), served admirably. In fact, the "turtles" won. Discipline beats no discipline, even if you are Rich Dennis, who had protected himself by hiring the turtles.
The moral of the story is, "don't be afraid to defy the boss if you honestly believe you're right." A good boss will respect that. S/he may even have hired you to protect him/her from himself/herself.
Many, perhaps most, bosses will be the "other kind." But they won't be worth working for. If you decide your boss fits into the latter category, then "keep your mouth shut" but find another job as soon as possible.
A summer intern once bet me that the Fed wouldn't raise rates on a particular occasion. I said the Fed would. The intern won. Then he explained why.
Was I impressed? Suffice it to say that I'll remember that intern for the rest of my career.