I'm constantly surprised by how many people don't wash their hair enough. We all have to wash our hair with differing frequencies. My friend only does hers once a week and it's OK. Yet I keep coming across people with revolting smelling hair. In theatres and cinemas, on public transport, and often even in the street, if the breeze catches the scent. Does it really smell so bad, or am I just hyper sensitive to the smell?