You're not supposed to wash your hair every day?
OK, that's another one I've never heard of. Why the heck not? I've been doing it pretty much since I was old enough to take my own shower (without my mother bathing me). And my hair is soft and silky. But yeah, I don't blow dry or treat it in any way. I wash it nightly (after doing my treadmill) and that's it. (Once, no repeat.)
Supposedly it easier to style and you don't dry it out.
But I wash my hair just about every morning and I do blow dry it just about every day unless I'm being lazy. I've tried switching to every other day and even attempted the shampooless process. Nope, my head feels greasy half way through the second day and I want to take another shower.
Even for people who can make less frequent hair washing work, there's an adjustment period. I used to wash my hair every day, and switched to every other day in self defense of my skin when I spent a semester abroad in Ireland (it was so much colder and drier than what I was used to that my rather-dry-anyway skin actually couldn't handle daily showers). My hair was a little greasy on day 2 for about a month, and then my scalp stopped producing so much oil and my hair stopped looking and feeling different on day 2. At the time, I'd have stuck with my every other day showers even if my hair had continued to be a hot mess, just because it was better than skin so dry it had lost elasticity.
I had another adjustment when I stopped using shampoo with sulfates, and again when I started stretching how long I could go without washing my hair, although I don't think either was quite as dramatic as that first one.
I've also just learned to be slightly less sensitive to extra oil that I know is there, but that other people don't notice. I've always been hypersensitive about that, because I have blond hair and extra oil makes my hair look darker. Part of my adjustment period was convincing myself that, no, other people did not actually have the ability to notice minute changes to the shade of my hair that even I had to scrutinize my reflection to see.
I wash my hair every day, but mostly because I am physically and mentally incapable of taking a shower and not washing my hair. And I have to take a shower every morning, even if for some reason, I had taken one the night before. However, I never rinse and repeat. I'm not sure anyone does.
I shower every day, because I go to the gym every day. Instead of actually washing
my hair, I just scrub my scalp with my fingers under the running water, and put (my equivalent of) conditioner on the ends to detangle. It still feels like washing my hair, there's just no soap involved. I don't like showering while trying to keep my hair dry, and my hair tangles easily and turns into a mess if I just get it wet without doing anything else. But using just manual scrubbing, water, and conditioner gets it clean and nice looking enough that I don't think anyone could tell you which days I actually wash my hair.
* I don't really "wash" or "condition" my hair as such, because I have been using the baking-soda-and-apple-cider-vinegar method for a long time now. Only I thicken both with guar gum these days (and add chamomile and other herbs to the vinegar), so they both function a lot more like standard shampoo and conditioner, in the sense that they are the right consistency to squeeze out of a bottle into my hand and then apply to my hair/scalp.