I would suggest that the reason to doubt what those in authority tell you is because those in authority got and maintain their positions by espousing the "party line"...and that is often in diametric opposition to the truth.
My favorite “big lie” of authority figures is that “conspiracy theories are crazy—it is impossible for that many people to keep a secret.”
Meanwhile every nation in the world, every major corporation in the world, requires classification of national security secrets and trade secrets.
If they didn’t believe a lot of people could keep a secret then what is the point of all of the classification and non-disclosure requirements?
They lie!