I have been using the same mug at work since I cannot remember when. Possiblly since I got back from traveling in 2004. I'm very attached to my mug - my mother bought it for me when I was 8, and it had my name on it. I drink a lot of tea at work - rosehip, peppermint, green, chai, black, you name it, and I just rinse it out after every use. In 2012, Cheryl, the department head's PA, started getting distressed at the build up of tannin, and kidnapped my mug and cleaned it. Then, in my last role Brendan who sat next to me was very distressed about the way the inside of my mug looked. I thought it was hilarious. I had last Thursday out of the office and accidentally left my mug in the kitchen, rather than on my desk and I came back to this:
My new colleague had scrubbed it clean! I think she was trying to be nice, but its going to take me another 6 years to rebuild the tannin art that was on the inside of that mug! In the meantime, onwards with tea to get me through my working day.