Wrong side of the bed
Q From Jim on AOL: I was hoping you could help me out. You’ve heard about getting out of the wrong side of bed? What is considered the wrong side? And could you give me a little history on the saying?
A The wrong side of the bed is the one that leaves you grumpy and unsociable first thing in the morning (my own has two wrong sides). There are many similar expressions that begin the wrong side of ..., of which the original seems to be wrong side of the blanket for a child born illegitimately. Some others are getting on the wrong side of somebody, the wrong side of the law, laughing on the wrong side of one’s mouth, and on the wrong side of forty (or thirty, or fifty, or almost any age, really).
All express the idea that there are good and bad aspects of any situation. A well-known American example, the wrong side of the tracks, is the only one of the set that seems to be based in a real, physical location.
Some writers say there was once a superstition that to get out of bed on the left side, the sinister side, led to bad luck, but this sounds like a well-meaning attempt to explain the mysterious. If there ever was such a belief, it’s not reflected in the recorded use of the expression, which is actually not that old; it seems to have been derived from another phrase of similar type.