Do you have rings inside your toilet at the water line? Or a crust at the end of the faucet? That's minerals. They attach to your hair in the same way.
I learned all this when I moved to a town with really hard water (lots of minerals) and suddenly my long hair started breaking off and I couldn't run my fingers through my hair, it felt awful. Then I went to a motel and with one wash - my hair was great again, as they usually have softeners. So, I went home and ordered a Culligan, I found that I wasn't itchy anymore, as minerals weren't sticking to my clothing or body either.
Have you nticed that your hair is wonderful after going to the beauty parlor? they usually have softeners too. It's just a matter of removing the minerals.
Now, I live where the water is fine, but I won't live without a softener, people on the street ask me what my secret is, (Cindy Crawford asked me also) that I must "have a secret", and there you have it, rinsing the minerals out.
Yes, humidity makes my hair swell up and curl, but it is still soft and silky, no split ends, and it's 30" long..