I once went on a vacation to the tropics with my then-boyfriend. We were on daily anti-malaria pills, Doxycycline. I had gotten my prescription from a Travel Clinic staffed primarily by female nurses. He had gotten his prescription from his male primary-care doctor.
The guidelines for the pills said to take them “1-2 days before traveling to an area where malaria transmission occurs.” We were traveling to Peru and spending the first week in the mountains, where malaria does not occur. He started taking his pills 2 days before entering the country; I started mine two days before entering the region where mosquitoes live–the Amazon basin. He repeatedly questioned my choice to wait to take my pills: “Don’t you want to start taking it now? We’re about to enter the country! You might get malaria” “We’re entering the country, but we’re staying in the mountains. We’re not entering the Amazon for seven days! According to these instructions, I don’t need to start taking the pill for five days.” This devolved into an argument (obviously) which finally ended abruptly when he said, “Well, my doctor said that we have to start taking the pill two days before entering the country. Don’t you think a male doctor knows more about this stuff than a female nurse?! Anyway, you are probably reading the bottle wrong!”
Never mind that I was reading the directions ON THE ACTUAL BOTTLE OF MEDICATION. Never mind that I had gotten the instructions from a travel clinic that dealt primarily with tropical disease. Never mind that malaria does not care about political borders (like, duh.) Never mind that either way, we were probably not going to get malaria. Nope. It all comes down to men knowing more than women.