The investor’s chief problem – and even his worst enemy – is likely to be himself.
– Benjamin Graham

If beating the market was as easy as becoming a top tennis player, there would be a lot more Serena Williams and Roger Federers. The lessons of acquiring skill in tennis are crucial for investors to heed.

Like most boys growing up in New York City, I spent much of my childhood and teenage years with a basketball glued to my hand. I was a fairly good athlete and even managed to make my college basketball team as a freshman.

That is not saying much.

Baruch College was a Division III school, and I mostly sat at the end of the bench. By the end of the season, I had accumulated more splinters than minutes played. I also played lots of baseball, softball and football. Unfortunately, since there were not many tennis courts in the Bronx, I did not get to play tennis often.

At the age of 25, I moved to San Francisco. Everyone there played tennis, so I became a tennis player. After a relatively short time, because of my athletic skills, I became a decent weekend player. However, I was often frustrated by the fact that players consistently beat me even though I was the better athlete. It was particularly frustrating when I lost to a player who was decades older.

After about 20 years, I figured it out.

While I was a better athlete, they were better tennis players – and there is a big distinction between the two.