I have to see it, and do it to actually get it. If you learn visually like I do then maybe this will explain the meter a little better.
Here is a visual of what your camera sees when looking at a scene made up of mostly snow. Apparently a histogram is important! Check out this visual from the cameras view point shot at f stop 8 / ISO 100 / shutter speed 1600 metered off exactly what the camera saw as middle gray:
Now if I open up 2 stops the shutter speed is now @400! Add light to light
When your meter is presented with black or white it freaks out a bit thinking way too much! For instance in the picture above I want the snow to be white when I look at the histogram it says white.