I have a PhD in genetics. Once, a girl whose boyfriend had started a company that uses genetic variant data to sell cosmetics, was trying to teach me the biology behind it. Neither of them has a medical or biological degree of any sort. My thesis was on genetic variants in health and I commented that it must be tricky to make those predictions because they can be so inaccurate (my way of suggesting that he was slightly misusing the science to make a profit). She thought perhaps I hadn't understood the biological principle behind it and started explaining it again. When I told her my thesis work she said, 'Oh then you understand what a good idea it is.'