oh that's supposed to be common knowledge...

So a few days ago, I got a video from a trans girl talking about how she takes care of her wavy hair. A lot of it I had heard before, but one thing that stood out to me was when she said to only put shampoo on the top of your head and conditioner on your ends.

I knew conditioner went on your ends, but putting shampoo on only the top of the head was very new to me, I had never heard anyone talk about doing it nor was I ever taught to so I tried it, and my hair came out so soft and shiny.

Yesterday I told my friend about it and she said "Yeah, thats what you're supposed to do" in the kind of tone that you could tell they meant "How do you not already know that"

Did y'all know that's how you're supposed to wash your hair? Am I just slow or is it not as common knowledge as she made it seem?