Goodness Rob, that chap Lawrence Krauss is a fascinating lecturer isn't he? I have no background at all in Cosmology (although I do rather fancy Brian Cox - ahem) yet I more or less understood what he was saying. I actually find it all frightening, but can't explain why exactly.
All that dark matter, and the fact scientists can measure the mass of the entire universe (and call it 'omega'- very biblical, "I am alpha and omega").
We visited the 'Our Dynamic Earth' exhibition in Edinburgh, and watched the superb film 'We Are All Astronomers' in the dome-shaped cinema. We both quaked with fear and awe as the Universe was demonstrated and explained.
Far from 'simple', I'd say it was 'mind-blowing'!