What the bleep does this CP violation really mean?

I’m a bit lost but from what I understand, the Big Bang should have produced equal amounts of matter and antimatter in which case everything would have cancelled each other out and the universe would be without matter. After testing the kaon particle decay and observing a difference in behavior patterns, it was shown that there was a violation of CP symmetry because (I think) theoretically according to the laws of physics, matter and anti matter should be created and decay at the same rate??