If you're from the upper hemisphere, northern Europe for example, then that's not surprising. I have a couple of friends who I've known for 30 years who are lac

If you're from the upper hemisphere, northern Europe for example, then that's not surprising. I have a couple of friends who I've known for 30 years who are lactose intolerant and had no idea that lactose tolerance is an evolved thing in northern Europe. https://en.wikipedia.org/wiki/Lactase_persistence https://en.wikipedia.org/wiki/Lactase_persistence