This is an interesting topic. I don't think that my palate itself has changed much other than the usual blunting of sensitivity which goes with ageing. However my experience has deepened and my horizons have widened and that means that my drinking choices are rather different from when I started on my wine journey.
That was in the late 50s and early 60s and at that time the only wines which mattered in the UK, where I then lived, were the classics "claret, Burgundy, champagne, hock, Moselle, sherry, port and Madeira"(sic). Prices, even for top names, were accessible for people in the professions and business management and even for the student and professional beginner, which I then was. The choice of all those wine types, except for Burgundy, was then good in the UK. Of course, we drank French "regional", Italian and Spanish wines when on holiday but very little at home.
The first widening of my horizons, but still limited to France, came while working in Paris and travelling round France in the 60s. I realised the charms of real Beaujolais chosen by bistrot owners, Loire whites and Cabfranc as well as Rhône reds in Paris brasseries and deepened my appreciation of claret during extended visits to Bordeaux helped by the wide availability of the wonderfully elegant 1953 vintage. However most of my buying at home, which by the later 60s was Belgium, was still limited to the classics minus Germany, whose wines were dismissed by the Bruxellois and Walloons as "étrangers"

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A second widening came with extended business visits to Spain in the early 70s, when mature vintages of top Rioja were available amazingly cheaply (c. the Peseta equivalent of about $1.50). It was clear that the quality of their best was similar to equivalent Bordeaux but it was nearly impossible to find them at home.
About that time and into the 80s, a vogue for New World wines, particularly from Australia and New Zealand, invaded the UK and some of northern Europe. I remember enjoying a crisp Kiwi SB in the early 80s, but saw no reason to buy them in preference to, say, Sancerre and still don't. I never really took to the goopy and oaky Australian style which became ubiquitous in UK supermarkets and lesser eateries, though I do like the wines of some Aussie boutique wineries like, say, Frankland Estate, Gossett, Clonakilla. Chile was a later invasion and the South Africa after the breakdown of apartheid. Though I like the style of most from these two better than that of commercial Aussie goop, I can't see any reason to prefer them in most cases to European wines made from the same grapes. Californian wine has never been much in evidence in Europe, I think because of price in the higher quality range and because of quality and style at lower price points. I have a few brought back from visits to the USA, very much appreciate Dominus, Ridge, Togni and am waiting to open a Montelena, Diamond Creek, Caymus SS and Opus One.
I have continued to love the classics but by the 90s the prices of Bordeaux and Burgundy were becoming increasingly inaccessible at top and upper-middle level. Helped by mentors like Liz and Mike Berry at La Vigneronne, Pierre Ghysens at TGVins and now at Moulin à Vins, Stefano Picchiori at ViniVins, Gert Claes at Alter Vinum and Roger & David Michel of La Cave des Oblats, my horizons now spread though all France, most of Italy and northern Spain. I am still keen to gain experience of unfamiliar appellations anywhere in the world especially where indigenous grape varieties are used.
Nowadays, my top five regions in terms of bottles consumed are Loire valley, Bordeaux, Burgundy, Rhône Valley and Tuscany.