"One word that accounted for Bill Gates' and my success: Focus"
The 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 what focus meant to Steve Jobs and how he applied it.
Focus vs Diversification
Buffett has also spoken extensively in the past about how excessive diversification in one's investments can be counterproductive.
Serenity too does a complete 17-rule Graham analysis; and nothing more. This is based on the same kind of conviction in Benjamin Graham's framework that Buffett, Seth Klarman and Irving Kahn have expressed.