But nothing is surer � while sex is one of the most popular conversation topics for teens and 20-somethings it remains largely taboo for those 50 and over. And this reluctance to talk about sex is part of the problem when trying to improve relationship and sexuality issues.
�What people don�t realise is that sex affects (everyone) whether we are having it or not,� the Curtin University graduate said.
�Sex is more than the physical act. It is an attitude and awareness that we bring into each relationship that we have, sexual or non-sexual.�
Ms Knudsen (24) set up her educational practice at Lifeskills Australia in January and has already noticed a trend among her small but growing list of clients.
Many have been mature women asking how they can increase the level of intimacy in their significant relationship.
�Most have been in a relationship for more than 10 years and their husbands don�t realise that sex and intimacy are different,� she said.
�Their husbands think that having sex all the time is being intimate. But it�s more about touch and consideration and having a good friendship. At the start of a relationship it�s lustful and physical but what lasts is having that friendship.�
Another trend is women�s libido. �Many women think they have no sex drive and that something is wrong with. They don�t realise that this can change. Libido is not set in stone,� Ms Knudsen said.
�They are not weird or alone or a prude. Women are like an oven, not a light switch; they have to be warmed up, it�s not like flipping a switch. And that�s where intimacy comes in.�
Ms Knudsen�s interest in sexual education began as a secondary education student at university.
�I did one unit of sexology and I was hooked,� she said.
�I knew I would have to come back to it at some stage, it always stayed in the back of my mind. My generation talks about sex all the time but even people in their 30s and 40s have a different attitude. When they were growing up they were told not to talk or think about sex. There�s still a stigma.�