Lip balm. Once a year I might need it so I buy a stick. I use it for a couple of days until I don't need it, then lose it. It might turn up several years later, but by that time I'd rather buy a new one.
Cheap biros. Has anybody ever used all the ink in one? They just evaporate somehow. Again, one might turn up several years later with an elderly cough sweet stuck to it, but you just throw it and get a new one.
Anything else?