Inconvenience → takes effort → high frequency of interaction between people and things → become dirty. Accumulating dirt itself is also an inconvenience (takes effort to clean up)
But, my mugs differ from other people’s mugs with a little stain on the handle slightly clockwise from the handle, because of my left-handedness, and make then personal and well-worn. Also the patterns made from jeans that haven’t been stone-washed.