Flat earthers explain the fact that almost everyone in the world believes in a round earth by claiming that we have all been indoctrinated by the world's governments, scientists and educators. The implication, and often the direct statement, is that we should believe only what we can personally verify or what seems logical to us.
But flat earthers believe lots of scientific claims that they cannot personally verify and that can't be logically deduced. For example, the world's government, scientists and educators have been telling us for a long time that the water molecule is made of two hydrogen atoms and one oxygen atom. Yet there is probably not a single person on this form, whether FE or RE, that is capable of proving this fact. And yet flat earthers believe it anyway.
So why do you flat earthers believe (assuming you do) that water has the chemical composition that you are told it has?