Let’s reflect on something that I’m sure most of us do. Whenever my shampoo bottle is nearly empty and I haven’t bought a new one, I dilute the few remaining drops with a bit of water.

This is usually followed by a period of denial that may last up to a month, during which I keep diluting the already feeble excuse for shampoo even more. What struck me was that this extremely diluted shampoo works quite well.

So here’s an astounding insight: we could actually buy an empty bottle alongside our new shampoo bottle, fill both bottles with half the shampoo, and use the same shampoo twice as long (perhaps even indefinitely, depending on your accepted level of dilution). You’re welcome!