Spending time alone is how you find out which opinions are yours and which were just on loudspeaker.

Opinions are contagious, and in constant company it becomes genuinely difficult to tell the ones you hold from the ones you have just been standing near. Time by yourself turns the volume down, and whatever is left when nobody is reacting is a decent indication of what you actually think. The aim is not to disagree with everyone. It is to know which parts are yours.

Take a question you feel strongly about and sit with it alone for fifteen minutes before discussing it. Write your answer down first. Then watch how much it moves once other people are in the room.