这个短语的字面解释是“起床的地方不对头”，这是什么意思呢？请看对话：

    A: What’s bothering you?

    B: I’m sorry I’m in such a bad mood today — I just got up on the wrong side of the bed.

    Note: This idiom means someone is having a horrible day. The wrong side of the bed is the left side, according to a superstition that goes back to the time of the Romans. People have been saying other people “got up on the wrong side of the bed,” “awoke surly or grouchy,” for well over three centuries now, usually not knowing the real meaning of what they are saying, but the equally old expression “got up left foot forward” tells the story. The supposedly sinister nature of the left is reflected in many English superstitions and expressions, such as the belief that it is unlucky to put your left shoe first, or to walk into a house left foot first. The Romans, especially Augustus Caesar, were very careful that they got up on the right side of the bed, but there is no evidence that they were less grouchy than anyone else.