Why do I have to heat hot water?? The only time it applies is on a recirculating system when you really are heating already hot water to a hotter temperature.

A lot of people don't think of the last letter being the abbreviation for the word, like Machine in ATM and Number in PIN, VIN.

There's all those clichés that are used all the time

Thinking outside of the box.
On the same page.
There are just too many to list and we hear them all the time.