Why won't my camera just take the picture?

I have a nikon D3100. I was out trying to catch a picture of lightning, during a heavy thunderstorm. My camera was too slow to catch it. I don't want it to take 10 seconds to focus, I just want it to take the picture. If it's not focused, too bad. JUST TAKE THE FREAKING PICTURE.

Turn off auto focus on the lens.set i to manual, manually focus it. Snap away.

Its mad at you

You're doing it all wrong

Read and Learn
http://www.weatherscapes.com/techniques.php?cat=lightning&page=lightning

Yeah… Blame the tool when the problem is the person using it. Of course the camera can't focus on a lighting bolt or a black sky. Set focus manually to infinity, and set your aperture and shutter, usually in Bulb mode, in full manual exposure mode. This way, the camera will take the photo the instant you push the shutter, (which should be done with a cable release or wireless remote).

You would be amazed what reading the owner's manual and other good photography books would do for your ability to use your camera properly.