This post was originally supposed to be about common sense.

Stop signs are universal. They are red octagons with white lettering — a standard that everyone recognizes.

I was going to write about the idea that we should have more global standards like this. Traffic signs differ significantly between countries and regions, and with a steady increase in global travel, it would make driving overseas so much easier.

But as I did a bit of last-minute research to make sure I didn’t look like an asshole. I learned that stop signs are not universal.

In Japan, for example, they are three-sided, like a standard North American yield sign.

Such a simple and relatively insignificant thing to learn, but it struck me because I thought I was right.

We all have these beliefs that we’re sure are true. Yet we rarely take the time to check — we trust ourselves sometimes more than we should.

We don’t know what we don’t know.

This is obvious in hindsight.

I suppose in a roundabout way, this is still about common sense.

Or, at least, the lack thereof.