The superfluous can be unnecessarily distracting from that which is both adequate and essential.
Warren Buffett on Focus
"One word that accounted for Bill Gates' and my success: Focus."
Definition of Focus
"When you think about focusing, you think focusing is about saying yes. No. Focusing is about saying No."
Jony Ive on Steve Jobs
Jonathan Paul "Jony" Ive — Chief Design Officer of Apple — explains how focus to Steve Jobs meant not just saying no to unimportant things, but sometimes even to a few important ones.
Focus vs Diversification
Warren Buffett has also spoken extensively in the past about how excessive diversification in one's investments can be counterproductive.
GrahamValue too does a complete 17-rule Benjamin Graham analysis and nothing more. This is based on the same kind of conviction in Graham's framework that Buffett, Seth Klarman and Irving Kahn have expressed.
Buffett about Graham
In the 2018 Balance of Power interview for Bloomberg Markets, Buffett says yet again:
"The principles haven't changed at all... It's exactly what Ben Graham wrote in 1949."