Let's hope you did not have any of the Enron stock. Maybe you know someone who did and lost everything, but you certainly might know several people who owned stock that lost almost everything. They probably aren't talking about it.
According to Investor's Business Daily newspaper there are 1,387 companies that lost more than 90% of their value from the highest point during the last 5 years. That is almost as bad as Enron except the folks that own this junk have hopes that someday their stock will go back up. And pigs can fly.
Do you realize that if a stock loses 50% from its high it must gain 100% to get back to the old high? And there are literally thousands of stocks that fall into that category. The people that own these dogs are waiting for them to rally so they can get out "even". What this means is that the stock has an effective cap or ceiling on it's price. Each time it sticks its head up it will meet with thousands of folks who will sell. The chance of it ever getting back to the old high is almost nil, never, nada, zip. From my experience as a professional floor trader on the exchange I can tell you it will take a minimum of 5 years of repeated rallies before the investors who are waiting to get out are finally exhausted.
There is a better plan. Why would anyone buy something and let it go against them 60 or 80%? Why do investors believe the greatest Wall Street lie of Buy and Hold? Psychologically people don't want to admit they are wrong. Your broker tells you you don't have a loss until you sell. Believe that and I have a nice bridge in Brooklyn I will sell you.
If you consider yourself a conservative investor then you must set limits on how much you are willing to lose if the stock you buy does not go up and instead goes down. One of the best rules of thumb is about 10% either from where you bought it or from its most recent high. That 90 dollar Enron stock would have been sold at about $80 and you would have a nice profit instead of a loss.
Your broker will discourage you from putting in a loss limit order called a stop-loss because then he will have to watch it which he won't. You see, and I know you know this, there is only one person who cares about your money and that is you.
Setting small loss limits when you buy something and following up a winner with a stop-loss so you won't give back profits you have made are the way to guarantee that your investments will grow every year.