a lot of people tend to go longer washing their hair due to the fact it doesn't smell, but there are a number of issues that happen on a daily basis that go on, that one needs to cleanse their scalp at least once a week. same thing with folks just washing their face with water. i have came across of a number of clients that do this and i see all kinds of yucky things under my mag lamp and wood's lamp. it doesn't have to be soap, but something with antiseptic properties that can remove debris and bacteria.
I agree.
I don't think most people can actually smell their hair (the smelliest part is near the scalp), or have become used to the smell. No matter if your scalp is dry or not, sweat, pollution, chemicals in the air, musk from your body or the environment, food odors, product buildup etc will stick in your hair and make it smell moldy, musky etc, and other people can always smell it better since they're not around 24/7. Other people are VERY good at picking up smells from others.
If you want to know how your hair smells to others, rub your finger on your scalp for a few seconds b) rub fingers down hair shaft really well