Lunar Eclipse: Dumb Guy Question

I don't care about the lunar eclipse tonight, but maybe because I'm not smart enough to appreciate it. This is what happens: The Earth blocks out the sun hitting the moon so it will seem as if the moon disappears.  Isn't that the same thing as a New Moon (the opposite of a full moon)? I think I know the answer is "no", but I have no idea why.

I don't understand the moon. The sun? Now that I get. I understand why days get shorter in the winter and longer in the summer.  I remember demonstrating the science with a cantaloupe and a girlfriend in my kitchen once. (She was not impressed. Should have used different fruit.)  And I understand that a solar eclipse occurs when the moon gets between the Earth and the sun (we had a cool one when I was in high school.)

But the moon I don't understand. When, say, half of the moon isn't visible once a month, what's causing that if it is not the Earth? In fact, what causes the shadows on all of those images above? To quote Antoine Dodson, I "must be really, really dumb."

Yeah, I could look it up, but I have you.