Ultimately, whether an object is a good or a bad depends on each individual consumer and therefore, it is important to realize that not all goods are good all the time and not all goods are goods to all people.
一个物品最终是好是坏，取决于每个独立的消费者，因此，不是所有的商品在任何时候都好，也不是所有商品对所有人都好，能认识到这点非常重要。