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.
Critical thinking skills are required, to really know if you’re right or wrong. Just going by what is common and doing the opposite, or doing what is common, is not enough.
The entire scientific method is designed so that people can verify if they are wrong or right, through falsifiable hypotheses, simply debating and using rhetoric to try to decide truth often leads to incorrect conclusions, if not outright falsehoods. However, the burden of proof is on the person with the new theory, not everybody else to prove the new theory is wrong
Such careful thinking, such scientificness, is rare as hen’s teeth.
It’s the only way to be sure you are correct or not.