Cramer's 'Mad Money' Recap: Invest Like a Pro

People need to worry about making too much money, not too little, because making too much money "is a sign that your portfolio is out of whack, that you're taking on way too much risk and that everything could fall apart for your investments at any moment," he said.

When Cramer was running his hedge fund he was "never more afraid" than when he was making huge money, he said. Market players should look at what they own and if they're "killing the averages," if they're making more money than they ever dreamed of making, then they are doing something "very wrong."

"You need to take profits immediately, start selling like there's no tomorrow, otherwise you're setting yourself up for a huge fall," Cramer said.

Finally, "amateurs try to game quarterly earnings reports to catch a quick gain," whereas professionals "learn to start living and stop worrying about the quarterly report," he said.

People, Cramer said, should never buy a stock in anticipation of a quarter. In fact, they should "actively avoid" buying right before the quarter or during earnings season in general, he said. "It's just too hard.

"On this show we talk about investing in stocks, trading stocks, speculating on stocks, but there is one thing that we absolutely never do with stocks and that is gamble because when you gamble, the house always wins," Cramer said. "Trying to guess whether or not a stock will go higher after it reports earnings -- that's gambling."