Flat Universe

So lately, scientists have been telling me that the universe is flat. No really, I'm serious, you can check and see what NASA has to say about this yourself. I found this amusing, interesting and confusing. The fact that we've gone from thinking the earth is flat to the universe is flat is humorous to me and will undoubtedly result in another drawing by me soon. Being a bit of a science buff, I was curious about this and after doing a bit of research vaguely followed their logic regarding the theory. However, the fact that the theory is largely based on things we have yet to really prove exist, such as dark matter and dark energy, I find it all slightly frustrating in addition to which I have trouble visualizing something exploding, as they believe the universe did, outwards in the shape of anything but a sphere. Well, enough of that, back to drawing... Cheers.