Brandes believes that all investors are prone to errors (and certainly we are not immune) which are often rooted in human behavioral traits that allow emotion to dominate reason.  

In order to minimize one’s own errors and seek to profit from errors of others, we believe it is essential to use a disciplined process and a team approach. A disciplined and consistent process focuses efforts on relevant fundamentals, not “market noise.” And a team approach can produce a thoughtful conclusion, less likely to be influenced by the emotion of any individual. Not only should those aspiring to be superior investors take advantage of errors of others, they should also aim to succeed by making as few errors as possible themselves. 

Source: “Why You May Be Your Own Worst Enemy as an Investor,” The New York Times, Oct. 12, 2018