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At a family gathering in August, I gave a brief tribute to my mother on the occasion of her 90th birthday. As the guests sipped their coffee in the warm summer air, I ticked off a dozen or so pieces of wisdom that she has imparted to her family over the decades. One insight that I credited to her was an aversion to waste. In our household, items such as clothes and toys would have multiple lives before being thrown out, and leftover food would be transformed into tomorrow’s lunch. In other words, my mother was an early advocate of the circular economy, in which materials and products have multiple iterations, and the waste of one process loops back and becomes the input for another.