Because if you spill it, it is bad luck, so to prevent it people throw salt over there left shoulder
A pinch of salt.
The firemans carry is when you pick someone up and throw them over both of your shoulders behind your neck.
Deucalion & his wife, Pyrraha, repopulated the earth at the instruction of Zeus, to throw stones over their shoulders.
peer over their shoulders...
spilt milk
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.
shawls, stoles, capes, serapes and ponchos are or can be worn over the shoulders. Shawls can also be worn over the head and shoulders.
Don't cry over spilt milk.
"It's no use crying over spilt milk!" is an idiom that means that something that you have no control over has happened, so it is no use feeling sorry for yourself.
Yes, it is possible. There is some people who threw balls at 100. And there are lots of people who can throw them at 95.
When you cry over spilt milk
make tea and invite people over