The market is a pendulum that forever swings between unsustainable optimism (which makes stocks too expensive) and unjustified pessimism (which makes them too cheap). The intelligent investor is a realist who sells to optimists and buys from pessimists.
Reality is a question of perspective; the further you get from the past, the more concrete and plausible it seems—but as you approach the present, it inevitably seems more and more incredible.
