You’re in the shower, and it’s time to shampoo. You flip the bottle around to read the instructions, and inevitably find the following:

Lather, rinse, repeat.

Let’s break this down into a flowchart.

Do you see the problem here? Nowhere does it state when you should stop shampooing. In other words there’s no “stop condition” in this set of instructions — it doesn’t say “repeat if your hair is still dirty,” it simply says “repeat.” Always. Forever.

If you follow these instructions, you will be in the shower for the rest of your life! I hope you’ve stocked up on enough shampoo to last until you starve to death in your shower of doom, lest you run out and be unable to follow directions.

But at least you’ll be clean when the coroner arrives.

No, the only choice you have is to NOT follow directions. You simply must disobey your shampoo bottle if you wish to live. It’s that important.

This conundrum calls into question many other instructions that you may follow blindly. If shampoo has misguided us, should we trust other directions? Maybe you should operate heavy machinery after taking NyQuil. Maybe you should let babies fall into plastic buckets. Maybe our pets should go in the microwave.

If we’re ever to trust product directions again, they’re going to have to change. As a first step, the shampoo manufacturers need to admit that we do not need to spend our lives trapped in the shower, lathering and rinsing.

Shampoo manufacturers, take heed: you need to add a stop condition to the directions to tell us when to stop and get out of the shower. Our lives are at stake. Thank you.