I've been eating yogurt just about every day for lunch since I was in grade 4. Yogurt generally is good for about 2-3 days after the "best before" date. However, I have had yogurt that literally expired on the date stamped on the container. Those weren't happy lunch days. In other extremes, our payroll adminstrator insists on grossing us out from time to time by eating yogurt that is weeks beyond the "best before" date. I think it all depends upon the brand.

And moldy yogurt is pretty gross.

If you freeze it, you can get another week out of it. After that, no dice.

you just know is all.

Is it like high pitched sounds and dogs?

When it unfreezes the texture is all... strange :) And yes, it can go mouldy. It turns colours and gets fuzzy. Except that it starts at the bottom, so suddenly your spoon will turn up a green or purple spot and you realize that you might not have noticed the other ones yet. I accidentally ate one, and it tasted incredibly gross. Also, I didn't die. Hooray!

Why have I lived so long as a yogurt eater and never encountered these end times?

c'mon, you can tell by looking at it. looks okay, you're gonna be okay. that's the yogurt rule.

What else is governed by that rule? Not used cars. Gotta be something.

just yogurt.

Is that why it is called the yogurt rule?

It's not a rule, it's a FORCE OF NATURE. Like water and how it seeks out toes clad in socks. Yo-Zam!

yo-zam? that's lovely.