Please don't call yourself dumb. Its unnecessary and untrue, I'm sure.
If what Battou said is correct, its cool for filters and whatnot. You can take that adapter, and buy, say a UV filter to protect your camera's lens (strongly recommended), or a polarizing filter which will cut out stray light.
Or, you can even get colored filters. Not to get into too much detail, but certain colors of filters will make black and white shots look very different. If you like black and white photography, your adapter will really be beneficial. Actually it will even if you don't take any B&W. Its just a cool thing to have.