Your view of coffee mug stains -- like that other famous glassware optimism metric -- is also a litmus test for your view on life. Sure, maybe your favorite daily coffee or tea cup is tarnished.

Scrub Daddy Cif had also been able to remove that telltale chalky texture that hard water leaves on dishes. Finally, I scrutinized the mug for any trace of coffee stains. I didn't notice any off ...

A dainty white coffee cup on a saucer is stained inside with a coffee ring. - Songsak Rohprasit/Getty Images ...