Two solid charts from a private wealth manager I respect.:

1) The best returns come from stretches after market P/E is low.  We all know this but just a reminder we are not at a low P/E currently.

2) Expect intra-year drops of 14% in the S&P - yet still make money in 34 out of 45 years.  

In other words, always be mentally prepared for a 14% drop in the market and likely more so in individual stocks.  Just part of the ride.  (and partly why I care about risk / reward - it's always bumpy and better to know how far you are from a fundamental floor in valuation).