It takes a certain kind of guts to say that, or where, common sense is wrong. And it isn't the kind of guts that's much appreciated. People will feel vaguely implicated. They'll quietly find excuses to dismiss you and what you say.

It's exactly why whistleblowers at organizations get ignored. Some observers will connive by trying to shut the person up, or paint them as unreliable or crazy. But many don't realize how they're playing along. They revert to their previous common sense without looking closely enough. They just think the whistleblower is a fool.

If you want to discount what a person says, you can always find a reason you'll want to believe. Is it a particularly good reason? You should be very suspicious of yourself here.