You know what sucks. Colleagues who steal your mug. There’s nothing more comforting than your own faithful mug when work is a drag. And ferreting through the mug cupboard for some half decent/not embarrassing mug to use if yours is missing is demoralising.
You’ll never have that problem again with this eternally dirty mug.
You will have “eternally helpful” colleagues who when faced with the obstinate stains might chuck it out – so it’s probably best to buy two.