Yes, I know about quantum mechanics, but with Feynman, I don't understand it.
He is supposed to have said, "If you think you understand quantum mechanics, you don't understand quantum mechanics."
And Heisenberg, one of the founders of quantum mechanics is attributed with saying, "Not only is the Universe stranger than we think, it is stranger than we can think."
It is as if every particle sends out waves of probability of what may happen to it in the future, one wave for each possible outcome, and that these waves can interfere with each other (much as sound waves or water waves can), even though this interference is describing possible events that haven't happened yet. Einstein doubted that this could be a complete description of physical phenomena, but merely an indication of our limited knowledge. He believed there must be "hidden variables" making the outcome of a particle experiment deterministic rather than probabilistic; i.e., that a particle "knows" what will happen to it, given the initial local conditions it finds itself in. Bell's theorem, however, proved this is not the case.