As an investor, it's always easy to know you made the right move when you look back. Hindsight is always twenty-twenty, CNBC's Jim Cramer said. But the "Mad Money" host knows that it's much harder to get things right in the moment, when things are emotional and you're trying to predict how something will turn out in the moment. One of the benefits of being an individual investor is that they don't have clients breathing down their neck who get angry when money isn't made every quarter. Unlike a hedge fund manager, individual investors can take their time waiting for a story to play itself out. "If you think that a stock deserves to go higher, whether because of a re-rating or a takeover or anything else that will produce greater returns, then wait. No one is looking," Cramer said.

Cramer's top investing mistakes

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In order to help investors become better at navigating the stock market, Cramer revealed some of the biggest mistakes he has made in over 30 years of investing. "Frankly, there are so many mistakes here that it might take a bit to explain them all," the "Mad Money" host said. He learned that when it comes to investing in commodity stocks, investors must know that it doesn't matter which ones they pick — like going for a better balance sheet or higher growth — if the underlying commodity is hit. If that happens, they will all go lower. Cramer thought he could avoid getting hurt by taking on a high-growth deep-value strategy, by only buying the highest quality companies for his charitable trust. He bought EOG Resources and Marathon Oil, and was wrong on both accounts. Cramer was also burned on Pfizer's aborted takeover bid for drug company Allergan, which had an overseas taxation rate that would allow the company to pay lower taxes than if it were based in the U.S. Both companies had specifically crafted the deal to meet the terms laid out for approval with the U.S. government on tax inversion laws. Just as the deal was about to close, the government changed the rules. Cramer didn't see this coming, and Allergan quickly shed 100 basis points on the news. "What did I do wrong? I trusted the government to keep its word," Cramer said.

The search for growth

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Cramer has become an expert at detecting an attractive growth story to hang on to, even when it's not the popular thing to do. "Solid growth stories are hard to come by, and when you find them, you need to hang on for the ride," Cramer said. It might be hard to remember, but Facebook was once considered a disappointing company that failed to live up to its potential for about a year after it came public. It seemed to Cramer that Facebook missed the entire migration to mobile from desktop, and the stock was pummeled. At that time, Facebook was trading in the $20s and Cramer started digging into the company's conference call transcripts. He found that the company not only reported a good quarter, but that as the company adopted the switch to mobile, advertisers were flocking to it. Cramer's charitable trust bought Facebook in the mid-$20s and was fortunate enough to catch a huge rally after that. He hung on to the stock because each quarter showed an improvement in the numbers and the stock's price to earnings multiple wasn't expanding. "You were simply paying the same amount for even bigger earnings growth. That is the best kind of situation," Cramer said.

The key to 'DIY investing'

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It seems to Cramer that the notion that investors shouldn't own individual stocks has become more popular in the last decade. "The industry of money management does you such a disservice on television, because the combination of their seeming perfection coupled with the debasing of your own abilities is a toxic brew for do-it-yourselfers," Cramer said. One of the principles of investing is to decide when it can actually be done alone, or if it is too difficult. A sobering example of this is anyone trying to profit from the pharmaceutical innovation with drug stocks. The key is to avoid a company that has only a few drugs in the pipeline that one day may or may not be approved for use by the FDA. They might be too risky, and never get approval and limp along forever. "When you have a drug company up against a difficult disease that many others have failed to cure, be more skeptical. There is a reason that others failed. It is an incredibly difficult problem to solve. The company you like might fail, too," Cramer said.

Don't be discouraged