To know that you have achieved more or less fully what you set out to do must give great contentment and peace of mind.

Robert Mondavi died in May 2008, a month short of his 95th birthday. He left behind a legacy that only he could have built and bequeathed - almost single-handedly he succeeded in putting Napa Valley and its wines on the world map.

The recent visit to Singapore by Margrit Mondavi brought back warm memories of Bob (everyone called him 'Bob') and Margrit, and reminded me how huge his presence was in Napa Valley.

Her visit emphasised yet again the great gap that has been left since Bob passed on.

No one, of course, is immortal, but some are more preciously missed than others, and Bob was one of those.

Volumes have been written, and by far more capable writers, about the place of Robert Mondavi in the world of wine.

Margrit Mondavi's visit here is the excuse for this tribute to a great wine man, and a great human being.

Bob and Margrit Mondavi visited Singapore for the first time some 20 years ago and in presenting his wines at dinner he said simply: 'I want to make wines which will be able to stand on the same table beside other great wines of the world.'

Those words come back every time I open a bottle of Bob's wines.

They summed up what drove him all the while he was building up the Robert Mondavi Winery and in so doing brought the wines of Napa Valley onto the world stage.

Bob Mondavi was to Napa Valley what Antinori is to Italian wine and Torres to Spanish wine.

On the many occasions that I visited Bob at his winery or was with him on wine trips, Margrit was always at his side.

It was a poignant moment then to see Margrit alone without Bob.

Two recent memories of Bob come to mind.

In May 2004, the Bacchus Society of America paid a visit to the Ribera del Duero to confer the society's Lifetime Achievement Award on Pablo Alvarez, owner-director of Vega Sicilia.

Bob and Margrit, as Lifetime Achievement Award members of the society, were with us.

Those who have visited Spanish wineries, especially the older traditional ones, will know that their cellars, all very old, are not the most comfortably accessible.

Steep, narrow concrete stairs, with no guide rails, lead down into dimly-lit underground rooms and unevenly cemented floors.

Bob insisted on visiting all the wineries listed on the Bacchus tour programme.

Oh no, he was not staying home. So there he was, accompanied by Margrit, walking slowly with her help and the aid of a walking stick, gamely (and successfully) negotiating the steep stairs down to the cellars. He was then 91 years old.

On the faces of the vintners we visited there was great awe and wonder.

Robert Mondavi was visiting them! Not in their wildest imaginations did they envisage a visit by such an eminent wine maker. Their knowledge of and respect for Bob was evident on their faces and in the way they received him. It was deeply moving.

Later, in autumn of that year, we paid what proved to be our last visit to Bob and Margrit.

We were their guests at dinner in their home in Napa Valley together with two other close friends. Bob was by then in a wheel chair.

By then too it was public knowledge that Robert Mondavi Winery had been sold to Constellation Brands, a huge wine and spirit conglomerate.

The mood was sober. Bob was not his usual irrepressible self. The dream had ended - but not the legacy.

That remains enshrined in the annals of Napa Valley, and will continue in the Robert Mondavi Institute for Wine and Food Science at the University of California at Davis to which Bob and Margrit had donated generously.

What of his wine legacy?

Mondavi's flagship wine was indisputably the Cabernet Sauvignon Napa Valley Reserve, a wine which many still regard as even greater than the iconic Opus One which Bob made in partnership with Baron Philip Rothschild.

The wine, mostly Cabernet Sauvignon with a little Merlot and Cabernet Franc, is made largely from the grapes grown in the famous To-Kalon vineyard in Rutherford, generally acknowledged to be one of Napa's finest vineyards for Cabernet Sauvignon.

Over dinner with Margrit we drank the Mondavi Cabernet Sauvignon Reserve 1987 and 1990 in honour of Bob.

Cabernet Sauvignon Reserve 1987

A famous wine from a great year for Napa, this 23-year-old wine showed a medium dark brick red, with just a hint of a pale rim.

A strong bouquet of ripe cassis with that characteristic cedary, slightly smoky, gentle scents of old oak and hot climate blackcurrant; mature but still vigorous on bouquet and palate.

Well concentrated, well rounded, giving a lovely mouth-feel, finishing smoothly and lingeringly.

A lovely wine; Napa Valley at its best.

Cabernet Sauvignon Reserve 1990

Another great Napa vintage, this tasted quite a bit younger.

A vivid brick red, a youthful cabernet bouquet which jumped out of the glass, vigorous and intense, followed by a more youthful, riper cassis taste with hints of coffee, liquorice and mintiness.

At 20, it is still youthful and will go on for five to 10 years before gently declining.

To those who maintain that Napa Valley wines do not develop beyond 10 years of age, these two wines give the lie.

Against those Napa Valley 'cult' Cabernets so much in the limelight today at astronomical prices, these Mondavi Cabernets seem anaemic, even weak.

But these are the classics, the legacy of a great winemaker, a great visionary and a big-hearted man.

Because one of the outstanding traits of Bob was his ready generosity. He was always ready to help, to give advice and to assist his fellow vintners.

His shoes remain too big to be filled so quickly.

This article was first published in The Business Times.