Agree! I do use soap occasionally (for "pits and pubes" or if I come back from a few weeks backpacking to get the deep grime out) but apart from that...no need, even after the gym.

I started out without shampoo about 20 years ago after reading a reference, just water and a vigorous scalp rub. My wife thought it was fine though I don't have long hair. And it seems absurd to put detergent in your hair followed by an additional product just to put back the oils removed by the detergent.