Over the years, Buffett's most memorable theme was the flightiness of "Mr Market" and the need to stay focused on intrinsic value. For Buffett, Mr Market – a character first conceived by Graham – was forever doomed to live with "incurable emotional problems", as he wrote in Berkshire's 1987 letter.

Many of Buffett's other recurring themes flowed naturally from that view of the market. If the market was manic and unpredictable, the key was to invest in a disciplined manner. Investors should only buy companies that they were capable of understanding and never be wooed by non-intuitive sales pitches and Wall Street esoterica.

He claimed no particular gift for timing the market, but insisted on making investments with a "margin of safety", another Grahamism that means buying at a price well cheaper than one's estimate of intrinsic value.

His retirement mark an end of a master. I still remember two of his quote:

"Rule No. 1: Never lose money. Rule No. 2: Never forget rule No. 1."

"The most important investment you can make is in yourself."