Repeat after me - Don't Worry

Why Investors Need to See the Light and Slow Down by Jason Zweig

In his classic book "The Intelligent Investor," the great money manager Benjamin Graham wrote that "the investor with a portfolio of sound stocks should expect their prices to fluctuate and should neither be concerned by sizable declines nor become excited by sizable advances." If you can't exercise that kind of emotional control, then by Graham's definition you aren't an investor at all.

Is the market overvalued? Is this a "real" rally? Do not concern yourself with such worries - find a good business, determine that it is fair-priced (or at a bargain!), and then buy it. Rinse and repeat.