The things in our lives that are well-loved tend to show it because unless we show our love by keeping them locked in glass cases, we often play a little rough with them.
Indeed, the relationship our things have with us is a lot like the one a young child has with the family dog. We'll squeeze and pet them much harder than we probably should and they sit there and take it with quiet dignity.
With that in mind, it only makes sense that the more time we spend using something, the more haggard it will end up looking as a result.