have one’s head in the clouds 字面意就是把脑袋放到天上的云里面，
someone’s head is in the clouds 形容某人心不在焉
Head, 头，clouds,云，in the clouds 在云里面，
上课的时候不要总是心不在焉：
Don’t have your head in the clouds when you are having a class.
他今天心不在焉，他是怎么了？
His head is in the clouds today. What happened to him?
过不去的就搁着 忘不了的就记着
t
