在 in another country 中，有这样一段叙述：
We were all at the hospital every afternoon, and there were different ways of walking across the town through the dusk to the hospital. Two of the ways were alongside canals, but they were long. Always, though, you crossed a bridge across a canal to enter the hospital. There was a choice of three bridges. On one of them a woman sold roasted chestnuts. It was warm, standing in front of her charcoal fire, and the chestnuts were warm afterward in your pocket.
作者写这一段的用意何在呢？为什么要提到卖栗子的女人呢？