Martha,
Presumably the money you "lost" in stocks when their value dropped isn't just gone, but will return when the value of the stocks go up. That kind of risk is the risk that money wont be available when you need/want it, a risk common to equities. The other kind of risk is that your money will lose value because of inflation, a risk common to fixed income securities. Balancing those two risks is an aim of asset allocation.
Now if you loaded up on trendy stocks near the end of of the last century, you may have lost money from overblown values that are unlikely to return anytime soon, but that wasn't wise investment practice then or now. A well diversified portfolio with an asset allocation plan you maintain is a better way.
Just buying bonds is a foolish as chasing high-flying stock, IMO.
db