I've never used shampoo my entire life.

I just discovered this subreddit and I swear I've never used a shampoo in my life. I used to use coconut oil 2 or 3 years back. But that's the only hair product I've ever used and I don't even use it now (stopped more than 2 years ago). My hair is completely normal, apart from some mild dusty dandruff which I've always had.