old head on young shoulders This expression refers to a child or young person who thinks and expresses themselves like an older more-experienced person. 这种表达是指孩子或年轻人虽然年纪小，却像一个年长的经验丰富的人一样思考和表达自己。 少年老成；年轻而有见识（的人）；人小鬼大 Even at sixteen, she handled the business negotiations with an old head on young shoulders. 她才十六岁，就能像个老成的人一样处理商务谈判。