Most of us just want to fit in, and believe what everybody believes.
Coming to your beliefs this way is not actually intelligent. We don’t do it consciously. It’s just tribalism or herding instinct or whatever.
So if everybody agrees with you then that’s a pretty good sign that you are wrong.
Things I must be wrong about because everyone agrees:
Flapping my arms won’t cause me to fly.
I can’t breathe underwater.
Washing hands prevents disease.
Eating food gives us energy.
Yesterday was Christmas.
If only everyone was as smart as you. 🙄