No. That is an old folklore expression.
Only if you believe in such things.
Right and left shoulder. God and the devil.
It is believed the "devil" stands over the left shoulder of a person. As salt was once considered a symbol of wealth and prosperity, spilling it is thought of as wasteful and a means to tempt the "devil" into taking it from you. Throwing salt over your left shoulder is supposed to "blind the devil" into not seeing the opportunity to reduce your material wealth.
The left. It is said the devil sits over your left shoulder, spilling salt is supposed to bring bad luck upon yourself, and trowing the salt over your left shoulder therefore "blinding" the devil so he doesn't know who to bring the bad luck on.
Traditionally the devil would be on the left shoulder, due to the belief that the left hand saide was the evil or sinister side. But really, you can get them on whichever side you want.
In America I have always been tought to "pass like cars" or pass left shoulder to left shoulder.
It is believed the "devil" stands over the left shoulder of a person. As salt was once considered a symbol of wealth and prosperity, spilling it is thought of as wasteful and a means to tempt the "devil" into taking it from you. Throwing salt over your left shoulder is supposed to "blind the devil" into not seeing the opportunity to reduce your material wealth.
It is believed the devil stands over your left shoulder and spilling salt is supposed to bring his attention to your "wastefulness" bringing bad luck. If this happens, you are instructed to throw the salt over your LEFT shoulder and "hopefully" into the devil's eyes, thus blinding him to your mistake.
Devil on My Shoulder was created on 2009-08-26.
Check your blind spot over your left shoulder, then your review mirror, then signal, shoulder-check again, then pass. Always, always, ALWAYS shoulder-check before signalling.
Salt, which has been spilled (something that happens frequently when people cook) is often thrown over the left shoulder. The belief was that the devil stood over your left (or sinister) shoulder, waiting for or causing your mistakes. The salt was supposed to go into the devil's eyes, blinding him to your errors.
The superstition of throwing salt over your (left) shoulder came about because people once believed the Devil stood behind your left shoulder waiting for you to make a mistake or to influence you into making a mistake. Spilling salt, which was once used as part of a Roman soldier's salary and hence as money was believed to not only be wasteful, but bad luck. Throwing some of the spilled salt over your left shoulder would be throwing it into the Devil's eyes, thus blinding him to your mistake.
Traditionally, if one is superstitious and spills salt, they should throw a pinch of salt over their left shoulder to ward off bad luck or evil spirits. This superstition comes from the belief that the devil tends to linger over one's left shoulder.