When Jim Cramer first started out in trading, he didn't like rules. He believed that either they couldn't really help, or they would cut his upside and prevent him from making more money.
After getting burned too many times, he learned the value of discipline.
"The rules protect you against your own bad judgment about what's going on at the companies you own or what's happening in the market overall," the "Mad Money" host said.
In order to really make money in the market these days, investors need discipline. Mistakes can cost you in trading, but if you do nothing with your money, you will have a whole lot of nothing to show for it.
Investors frequently ask Cramer what to do with a stock after it has had a hideous decline. His first response is always to ask why they bought the stock in the first place.