Why does almost every culture have some weird relationship with salt?

I started reading about this after buying Celtic Sea Salt and it's kind of everywhere.

Throwing salt over your shoulder, bread and salt as a welcome, salt in rituals, salt as protection, salt used to preserve basically everything.

For something we now keep in a shaker next to the stove, people have attached a ridiculous amount of meaning to it.

What's the salt thing where you're from?