Do you know that for many Russian speakers "permanent" means "temporary"? Even though any Russian dictionaly will tell you that "permanent" is "permanent"?
The story of how it all came to be is a good illustration how the semantic links work.
Most Russian speakers, unless they grow in a test-tube academic environment, first hear the word "permanent" in the context of hairdressing, meaning a kind of a chemical treatment that makes your hair curly. What the haridressers meant, when they coined the term, is that the treatment will last for a long time, much longer then whatever was available before. Long enough, actually, to last until the client's next visit, which from a hairdresser's perspective is as good as forever.
The clients, however, see things differently. For most people on most occasions, the time when you look at yourself in the mirror and go "Oh, [your favorite emotional expression], my hair's a mess, I gotta get it fixed" comes all too soon. In other words, there's nothing about your hairdo that will last long enough. Including the curly treatment. From an average client's view, it is something that will be there only for a while, and then will have to be renewed or updated. And it's a pretty short while, if you think of it.
That is how, unless you face the real meaning of the word more often than the hairy context, you're left with the impression that "permanent" has to do with your hair, everything that has to do with your hair is temporary, meaning "permanent" is "temporary".