I can certainly see why it would upset you that people are not only not thanking you but apparently persistently stealing from you. Yuck.

But I have to say that the cutlery in my own house disappears at almost the same rate as you are experiencing in your lab, and THERE ARE ONLY THREE PEOPLE THAT LIVE HERE. I just can't imagine where it goes. Between the cushions of the couch? Under Thorin's bed? Maybe under furniture in the attic (which is also the TV room)? Or into some other dimension, where it is hanging out with the missing stuff from your lab??