Shampoo ? What’s that?

People wash their hair waaaay too much. I use shampoo in my hair once a month; the rest of the time I just scrub it with water and my fingers, and I very rarely have dandruff. Mind you, my skin is quite oily, but when I was a teenager with super long hair I washed my hair with shampoo every day and my hair was fried as fuck. Also, I think it contributed a lot to my extremely bad acne, which I almost never get anymore.