Down to his last $30 billion -- Bill Gates is finally logging off...
He is a man so rich that it has been said that if he saw a $10,000 note lying on the floor, it would not be worth his while to pick it up.
According to this legend, in the seconds it takes to bend over and grab the money, Bill Gates would earn more by simply getting on with his work.
But will this still hold true when the Microsoft tycoon steps down from his management role this summer?
Then the man described as the "Pope of Technology'' will have plenty of time to lean over, as well as indulge his fondness for reading, playing golf and bridge. Not to mention one of his biggest passions, philanthropy.
The computer tycoon, the first or second richest man in the world (some reports suggest he has been overtaken in the past year by the Mexican telephone tycoon Carlos Slim), delivered the keynote address at the world's top technology trade show in Las Vegas for the 11th and final time this week.
When Gates stands down it will be a milestone. The man who made his fortune bringing personal computer technology to the masses is finally logging off, and when he does, computers will in some ways be old hat.
When he started Microsoft -- a compression of microcomputer and software -- 33 years ago, computing was an esoteric occupation, largely confined to a smattering of Geekish nerds, who looked and acted like Gates himself. Now, thanks to the Internet, it is a mass medium that is rapidly superseding television.
As Gates looked forward to retirement from Microsoft this week he pondered with characteristically laboured humour about what he might do in his retirement. At the computer show, he showed a video featuring some of his friends.
Inevitably Bono pops up in the video. He jokingly squashes the ambition of the world's best known businessman to replace the Edge as the guitarist of U2: "Bill we can't replace Edge just because you got a high score on Guitar Hero (a popular computer game)."
In one segment, Bill was shown working out with his new "personal trainer", the actor Matthew McConaughey. And both Hillary Clinton and Barack Obama turn him down as a potential running mate in the presidential election.
As well as accumulating what was at one time the biggest fortune in history, it is often forgotten that Gates has also lost billions along the way. When the Microsoft share price plummeted at the start of the decade during the dot com crash, financial observers noted wryly that he was down to his last $50 billion.
Gates did not revel in the title "the world's richest man''. "I wish I wasn't,'' he once said, possibly irking ordinary mortals who play the Lotto every week. "There's nothing good that comes out of that.''
The web site, Bill Gates Net Worth, now estimates his fortune at $28 billion. This means that he could give every person in Dublin city over $40,000 and still have plenty of change.
Partly as a result of the drop in share values, dedicated observers of the Bill Gates fortune now estimate that he has to get by on earnings of $25 million a week.
When he quits the Microsoft office in the summer, Gates will probably not miss the four million emails, which he receives every day. He is the most spammed person in the world.
Ironically, tens of thousands of these emails are spam telling him how he can get rich. Computer filters and his minions have the job of whittling down his mail to just 100 messages a day.
He will now concentrate on the work of his charitable organisation, the Bill and Melinda Gates Foundation, which has already assigned over $28 billion to charity.
Reflecting on four decades in the technology industry, Mr Gates stressed that the future of the company was in good hands, even though the change would be a big adjustment for him.
"It will be the first time since I was 17 that I won't have a full-time Microsoft job," said Gates. "I'm not sure what the last day at work will feel like."
Gates was never the greatest computer innovator. Technological observers have often remarked that his real talent was to knock out rivals through business acumen, ensuring that his products are used in the vast majority of computers across the world.
Time magazine once remarked: "Gates, grown very powerful and great, sits at the centre of the technology world like an immense frog eyeing insect life on the pond surface, now and then consuming a tasty company with one quick dart of the tongue.''
Having accumulated his vast fortune, Gates now seems determined to give it away. His wife says she hopes he will be remembered as much for his philanthropy as his technological feats.
The Gateses now hope to use their wealth to save the lives of poor children, spelling out a principle that may seem strange, coming from a couple whose fortune is as big as the Gross Domestic Product of many small countries:
"All lives -- no matter where they are being led -- have equal value."