LOL. This is suppose to be fun!
Don't sweat it dude, you can totally ignore it, BUT I would screw down the spots that have nearby components you may connect disconnect, like around the ram, around the expansion slots, around a bunch of headers. Just a little detail, don't sweat it.
And I hate these case vendors, will it kill them to throw in a couple of extra spare screws, does it cost them that much? GGGGGRRRRR.