One of the things I emphasize most in my community is that there are no certainties in the markets. People want concrete answers when such answers don't exist. The stock market has an element of uncertainty... if you study a lot, that part will be small, and if not, it will be large.

Just as no single stock market ratio is good or bad by itself, but rather must be looked at in conjunction with all other ratios based on the business and sector you are studying.

But it's not just the stock market, the same thing happens in life, nothing is good or bad by itself, everything has its light and shadows.

The important message is that in markets, as in life, there are no certainties; the only thing you can do is avoid as many red flags as possible.

• Roads allow us to go from one place to another and connect us, but many people have died on them.

• You can exercise and eat healthy to live longer and better, but there are people who die young and take great care of themselves (although their chances are lower than someone who eats donuts daily, but they exist)

• Technology connects us more than ever… but it also isolates us more than ever.

• An Olympic athlete prepares for years for everything to be decided in a few seconds; if they fail in those seconds, it's over. But they train to fail as little as possible.

• Just as in the markets, a low PER might seem like a great opportunity… but many times it reflects a declining business.

• A high ROIC is attractive… but if there’s nowhere to reinvest, growth slows down.

• Stock buybacks seem good… but if done at a high price, they destroy value.

And so I could go on and on... get it into your head that there are no certainties in the stock market. There is study, progress, and experience. And anyone who sells you certainties is deceiving you.