The Moon's Reserves of Water

While our earth is tilted about 23 degrees and so as its orientation relative to the sun changes throughout the year, everything gets struck with sunlight pretty much. The moon however is only tilted like a degree and a half and that little tiny tilt means that there are craters on the north and south pole that when you start working out the geometry and the depth of the craters, the sun literally doesn't shine there. Ever. And it's weird because you can also go to the place where the sun always shines. Yeah. So why do we think that there are reserves of water on the moon? Well- Or I guess why did we think?So before we confirmed them, why did we