Because they're human, and humans have a hard time imagining how very different conditions can be.
I know someone who had a hard time raising basil, which mystified me. What could possibly be hard about raising basil? You put it in a pot on a windowsill and water it when it's looking a little limp and it grows.
My friend was living in Wales. Basil needs more sunlight than occurs naturally there.
Left to myself, I never would have believed that water boils at different temperatures in different places. It sounds like a practical joke, but there's good physics behind.
I think we need a discussion thread for the californian drought going on. I would like to compile information in the main post and would like help compiling it. If we really are proud to be effective altruists then this is an area we should really figure out.
Any one have any good ideas on how we can help?