核心问题
我知道 I was not the least tired. 意为：“我一点也不累。”His mother did not in the least understand him. 意为：“他母亲一点儿也不了解他。”因此，We were very impressed by the new school, not least its own swimming-pool. 应当译为：“新学校给我们留下很深刻的印象，但是它的游泳池一点儿也没有给我们什么好印象。”译文对否？
词典解答
not the least, not in the least 这两个短语与 not least 的含义是完全不同的。not the least 与 not in the least 作“一点儿不”“根本不”解。但是 not least 则具有完全不同的含义，它常常引出重要的例子或理由（尤其是，特别是，部分地，主要地）：
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... all western countries, not least the USA(EED) ……所有西方国家,尤其是美国
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The programme was moving, not least because the narrator had the best voice in broadcasting. 节目很动人，主要是因为播音员的嗓音极好。
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Trade has been bad, not least because of the increased cost of rubber. (LDCE) 生意一直不好, 主要是因为橡胶价格上涨了。