There was a flight of concrete steps leading from the Fifth Street entrance of the main library in Los Angeles, and I remember how a half century of patron's footsteps had worn into them shallow depressions. After I left Los Angeles, the library was expanded and renovated, and I don't know if the steps were rebuilt or not. They were smooth and shiny, and a bit slippery, so I suspect that they were deemed a hazard and replaced, or covered with some new surface. I doubt that I would like them. Wear often pleases me. Climbing those steps always gave me an image of the countless books which had been carried up and down them, and the echo of my own steps in the stairwell was like the echo of the steps of all the people who had carried all those books and had collectively formed those concave marks, the subtle shapes of which I could feel through the soles of my shoes.
The wear would also make me think what a splendid ruin the building would be if Los Angeles were ever abandoned. I could imagine future archaeologists removing tons of rubble from caved ceiling and partly fallen walls- soil-choked chunks of concrete laced with twisted rebar and the delicate but persistent roots of plants- and at last finding those stairs, and seeing the marks of all those generations of footsteps. I liked making them a little bit deeper every time I went there.
But I also knew that if Los Angeles were not abandoned, the stairs would eventually have to be replaced. The tough concrete of the Romans might endure long centuries of intensive use, but the concrete of the industrial age is apparently softer stuff. Mere shoe leather had already diminished those stairs considerably, with just a few decades of use. That's why we use disposable floor coverings, which can be easily taken up and replaced when they have become worn. Even stone wears away in time, if it is exposed to such use, so I suppose that the modern way of frequent renovation makes sense. Still, I'm saddened at the thought that, when the tatty synthetic carpet or the worn vinyl flooring is tossed away, the living evidence of its users is discarded with it. Eventually, should the realm of technology prove to be sustainable, I suppose there will be materials invented which simply do not wear out, or wear so slowly that they outlast stone by ages. A time might come when patina is the rarest of commodities. I can't help but think that such a world, in which transience had been denied, would be profoundly disturbing. Perhaps that is one reason why, when I see the exposed concrete of my front walk, pocked by weather and polished by footsteps, I rejoice in its decay.