All investors wish they could be right all the time, or something close to it. But in his latest for Seeking Alpha, Validea CEO John Reese says that trying to be right all the time is unrealistic — and potentially dangerous.

“When an investor like Warren Buffett amasses a fortune of tens of billions of dollars in large part due to his stock market savvy, or a mutual fund manager like Peter Lynch doubles the market average for over a decade, it’s easy to imagine that they are close to infallible when it comes to stock-picking,” Reese writes. “After all, to be that successful, an investor has to be correct the vast majority of the time, right?”

“Nope,” he continues. “While they likely make good calls more often than bad calls, the truth is that even great investors lose money on a lot of their stock picks. When you are dealing with a financial machine that has as many moving parts as the stock market, expecting to be right on 100% of your picks (or 90%, 80% or even 70% of your picks) just isn’t realistic. It’s also not necessary — and, in fact, it can be quite dangerous.”

Reese looks at how often his best-performing Guru Strategies are right on their picks. And he talks about why thinking you can be right all the time can lead you to panic when things don’t go your way, causing you to ditch a good strategy at the wrong time.